Forensic Field Skills Flashcards
What did Locard believe?
No matter where a criminal goes or what he does, he will leave something behind and take something away.
What is Locard’s principle?
Every contact leaves a trace
What did Karl Landsteiner do?
He discovered human blood groups in 1901.
What did Revenstorf do?
In 1904 he claimed that diatoms could be used to distinguish ante-mortem from post-mortem drowning.
Where was the first British forensics lab established?
Hendon
When was the FBI established and by whom?
1905, Theodore Roosevelt
When did Watson and Crick discover the structure of DNA?
1953
When were dental records first used for ID?
1940s
What does AFIS stand for?
Automated fingerprint identification system
Who first used Gas chromotography - mass spectrometry for forensic use?
Zoro and Hadley in 1976
Who discovered a method of identifying individuals from DNA?
Sir Alec Jeffreys
When was DNA profiling first used to solve a crime?
1986 (Colin Pitchfork)
When did world’s first national DNA database in the UK commence operations?
1995
What is the CSI effect?
The unrealistic expectation of jurors wanting to see DNA, fingerprints and trace evidence.
When did the forensic science service launch the UK’s first online footwear coding and detection management system?
2007
What does the CSI effect not consider?
- Not all scenes are evidence-rich2. Not all techniques/equipment seen on TV really exists.3. Evidence may be compromised
What is a crime scene?
Any location where a criminal offence has occurred or any place that contains physical evidence.
What is the golden rule of crime scene investigation/management?
Never touch, change or alter anything until it has been identified, documented and measured…when a body or article has been moved, it can never be restored to its original position.
Exceptions to the golden rule:
- If the potential exists that an item of evidence could be used to cause harm/death to someone at the scene.2. If the potential exists for an item/evidence to be lost/contaminated or destroyed.
What is the role of the first response officer?
Approach -> Preserve life -> Arrest perpetrators -> Safety issues -> Secure and protect -> Identify witnesses.
What is the meaning of secure?
Secure is to “close access”.
What is the meaning of protect?
To “deny access”
What measures can be taken to secure a scene?
- Tape2. Cones3. Police officers4. Vehicles5. Fences6. Walls7. Buildings8. Any impermeable landmark
What is an inner cordon?
The area of the incident and crime scene.
What is the outer cordon?
Seals off an extensive, surrounding the inner cordon. All access and exit points will be controlled by police. The control/command vehicles of emergency services will be positioned between the inner and outer cordons.
What is a common approach path?
The only entrance to a scene.
Who to deny access to?
Anyone who is not there to record, collect or preserve evidence.
Generic roles of the first response officer
- Access scene2. Establish communication3. Emergency services deployed4. Commence scene log5. Protect any transient evidence6. Try to identify deceased and suspects7. Gather details of potential witnesses8. Conduct preliminary risk assessments
The role of the first supervisory officer
- Reviews first officers works2. Sets perimeter of scene/cordon/CAP
Category A crime
A major crime of major public concern
Category B crime
Routine major crime when offender is unknown.
Category C crime
A major crime when the identity of the offender is apparent.
Key players at major crime scenes
- First response police officer2. Uniform supervision3. DS4. Scientific support coordinator5. Crime scene manager6. Crime scene investigation team7. Force medical examiner8. Other specialised personnel
Specialised personnel roles…
Are UNBIASED. They also seek to exclude the innocent and assist prosecution of guilty
What is the role of a Forensic pathologist?
- Conducts post mortems2. Find cause, manner and time of death3. Authorised by Home Office4. Medical degree +2 yrs training
What does a ballistics expert do?
Analyse bullets, firearms, ammunition and impacts to establish the firearm used at a scene.
What does a Forensic scientist do?
- Assess 2. Examine3. Interpret4. Identify5. Liaise with SS personnel6. Report7. Court recognised expert
What is forensic entomology?
The use of insects and their arthropod relatives that inhabit decomposing remains to aid legal investigations.
What does a forensic entomologist do?
- Attend the scene and collect insect and weather data2. Use the data to estimate PMI3. Expertise is location specific.
What is forensic Anthropology?
It serves the investigative and judicial communities by analysing human remains for medicolegal purposes.
What does a forensic anthropologist do?
- Attend scene to recover remains and soil samples.2. Full exam in lab3. Help establish ID, cause of death and social/habitual characteristics.
What does a senior investigating officer do?
- Manages the enquiry2. Maintains policy documents in relation to all actions completed.3. Chairs strategy meetings
What does a scientific support coordinator do?
- Designated in major/multiple scenes2. Liaises with scene managers, specialist forensic service providers and SIO3. Attends strategy meetings4. Controls budget for forensic examinations
What does a crime scene manager do?
- Manages crime scene team2. Allocates tasks3. Liaises with crime scene coordinator/SIO4. Carries out initial and final walkthrough5. Responsible for health and safety of team6. Manages contamination, continuity issues and integrity of scene.
What is the overall protocol of the forensic team?
- Assess scene2. Examine scene3. Record detail4. Disclose everything5. Forward evidence6. Advise and communicate
What does an exhibits officer do?
- Responsible for secure storage of all forensic exhibits.2. Attends scenes, searches and post mortems3. Ensures continuity of exhibits4. Prioritises exhibits5. Responsible for health and safety issues in relation to the handling of chemically treated exhibits6. Ensures exhibits are available at court (attends)7. Ensures all exhibits have been disclosed to defence.
List required personnel at a crime scene team.
- Crime scene manager2. Forensic scientist3. Photographer4. People to retrieve forensic samples5. Fingerprint experts6. Exhibits officer
What details are required in the exhibits book?
- Entry number (Initials and #)2. Description of property/item3. Witness reference no.4. Court exhibit no.5. Where found6. Found by7. Time and date found
Why is PPE worn at the crime scene?
To avoid contamination of evidence from the person collecting it.
What are stepping plates used for?
To avoid damaging evidence on the floor such as footprints.
Name the four search techniques.
- Parallel2. Grid3. Zone4. Spiral
What is trace evidence?
Any object that can establish that a crime has been committed or can link a crime and its victim or the perpetrator.
What are the different types of glass with examples?
- Sheet - sheds/greenhouses2. Float - windows3. Pattern - privacy4. Toughened - glazed doors/tables5. Laminated - windscreens6. Wired - fire doors7. Container - bottles/glasses
How is contamination avoided?
Avoid situations whereby same officer deals with victim and suspectSuspect’s exhibits and other exhibits must be kept apart*Exhibits must be packaged and sealed immediately
How does contamination occur?
Introducing evidence to the scene that was not originally therePoor examination and handling of exhibitsPoor packaging of exhibitsUsing contaminated equipment
What are the effects of contamination?
You are the custodians of evidence. If the evidence is not collected in the correct way, the science can be thrown out of court
What are the three main considerations for exhibits?
- Integrity2. Continuity3. Packaging and Handling
What aspects must an exhibit have once collected?
- A form of signature seal- Continuity of exhibit label- A backup label- Clean, sterile containers/packaging is always used
What 10 pieces of information must the exhibit label contain?
- Police force2. Station code3. Description of item4. Where found (full address)5. Where found (within the address)6. Date found7. Time found8. Exhibits reference9. Signature of recovering officer10. Signatures of all subsequent people that handle the exhibit
What must be considered when handling exhibits?
- Always wear gloves- Take the packaging to the exhibit - not the other way round- Do not let the object come into contact with you or any other contaminated area- Deal with each exhibit independently- Do not leave unsealed packaging around the office
How many skeletons did Wingate Todd collect and when?
2600 individuals between 1912 and 1938
What is a documented collection of skeletons?
A set of skeletons with pre-known sex and age
How many skeletons did Robert Terry and Mildred Trotter collect and when?
1636 individuals between 1914 and 1965
Why are four fields used in Anthropology in North America?
It provides a holistic approach to the study of humans
What are the four fields in Anthropology in North America?
- Physical- Archaeology- Social - Linguistics
Where were the first international forensic anthropology teams working?
Argentina, Guatemala, PHR, and ICTY
What is the official name for the ‘body farm’ and where is it based?
Anthropological Research Facility, Tennessee, Knoxville
What British associations are there for forensic anthroplogy?
BAFA (British Association for Forensic Anthropology) within BAHID (British Association for Human Identification)
What tasks are there for a forensic anthropologist?
- Locate and recover remains- Anthropological analysis including:* Establishing the biological profile* Trauma analysis * Estimation of the post mortem interval (PMI)* Identification
What kind of cases do forensic anthropologists work on?
- Fresh bodies: aging and trauma analysis- Aging the living (young offenders)- Cases of historical interest- Mass disasters (Disaster Victim Identification (DVI) teams)- War crimes and crimes against humanity
What are three things archaeological and law enforcement techniques employed for?
- Site location- Excavation- Documentation
What five techniques can be used to determine site location?
- Aerial photography- Vegitation changes- Ground Penetrating Radar (GPR)- Soil changes- Probing
What is stratigraphy?
The study of soil layers (strata)
What is the law of superposition?
Strata that are younger will be deposited on top of strata that are older, given normal conditions of decomposition
Can the exact same approach be used for all graves?
No. Each grave is different and so each requires a different approach
What will affect the law of superposition?
The creation of a burial pit as it will disturb the layers of soil
Why should care be taken when excavating?
Excavation is a destructive process and we need the maximum amount of evidence recovered, so it is vital to document each step.
Heavy machinery is used until…
the burial level is reached.
What should be used to excavate when the remains are found?
Small hand tools.
What must be first observed of the scene?
Orientation of body/ relationship to artifacts.
What must take places at all stages of the investigation?
documentation - notes/sketches/photography.
What must the soil first undergo?
Screening.
What questions will an anthropologist ask first?
- Is the material bone?2. Is it human bone?3. How many individuals?4. How long ago?5. Are they of forensic significance?6. What is the individuals profile?7. Are there any unique anatomical features/pathologies?8. Cause of death?
Why can smaller fragments be hard to identify whether bone or not?
Lack diagnostic features.
Why is there confusion between human and non-human bone?
- Absence of a cranium2. Not familiar with human skeleton and variation.
How can small fragments be identified?
Microscopy or chemical analysis.
What are common differences between human and non-human bone?
- Size, shape, texture2. Histological differences
How many cases are reported to be be non-human bones?
30%
What is used to determine the MNI?
Anatomical relationship, duplication, size consistency and joint articulation.
What does MNI stand for?
Minimum number of individuals.
Sex determination…
- Only reliable in adults2. Skull & Pelvis (morphological methods)3. Rest of skeleton (metric methods)4. DNA last resort (subadults & fragments)
When determining age, why are different methods required for adults and subadults?
Development & degeneration
How are subadults aged?
- Long bone lengths2. Tooth formation3. Tooth eruption4. Epiphyseal union
How are adults aged?
- Pubic symphysis2. Auricular surface3. Sternal rib ends4. Cranial suture closure5. Dental attrition6. Histological methods
How is ancestry determined?
Caucosoid, Negroid, Mongoloid. Europe, Africa, Asia
Which ancestry traits are centered on the skull?
- Nasal area2. Zygomatic bones3. Jaws4. TeethOther postcranial elements can be used but not as reliable.
What is the cause of mixed traits?
Mixed ancestry.
How can we estimate stature?
- Correlation between bone length and stature2. Development of regression equations from individuals of known stature3. Lower limb long bones are more reliable4. Population specific - correct formulae must be used.
What other useful form of identification can be found on the bone?
Pathologies leave traces on skeleton which can be traced with medical histories, narrowing down the field.
What is PMI?
Post-mortem interval.
What is time since death based on?
The principals of forensic taphonomy: 1. Associated artefacts, smell, texture and presence of soft tissues.2. Chemical analysis3. Ultraviolet light (questionable)4. Other disciplines such as entomology and botany.
What possible causes of death are there?
- Blunt force trauma2. Sharp force trauma3. Projectile trauma4. Miscellaneous trauma
How is a positive identification proved?
Comparison of antimortem records with postmortem findings.
What anti-mortem records can be used for comparison?
- Dental records2. Medical records3. DNA analysis
What should a case report include?
- Background of the case2. Search & recovery3. Details about anthropological analysis including all techniques used4. Summary of findings.
What complementary methods are there to compare a positive identification?
- Photographic superimposition2. Facial approximation
Why must a case report be clear and understandable?
- It is a legal document2. It may be used by investigators and attorneys and become part of court proceedings.3. Must be understood by jury4. Author may be called as expert witness.
What is a Clandestine grave?
Not a ritual burial, concealing the body from police
What are the steps for searching a scene
- Collect information2. Prioritise3. Choose search strategy4. Survey5. Detect anomalies6. Excavate
What sources of information are available to investigators?
- Witnesses2. Confessions3. Intelligence
What is the only evidence that proves the presence of a clandestine grave?
The forensic archaeological excavation
When doing a line search, how dispersed should people be?
2-2.5m apart
What various strategies for searching are there?
Going up/down hill, spiral, corridor, criss-cross
Why the specific distance between searchers?
the peripheral vision is most detailed and overlaps with adjacent searchers line of view
What do you look for during a search?
Changes in soil and vegetation
Why might changes in vegetation and soil be evident?
Decomposing flesh fertilizes soil improving vegetation growth
How is evidence found and marked at the scene?
It is pointed to by a searcher and recorded by the evidence collector. it is then marked with a flag
What are the best conditions in which to perform a search?
- Oblique light (sunrise/sunset)2. Artificial lighting at night3. After rain or snow
What other potential indicators are there for suspicious activity?
Abnormal entomological activity and traces of passage
What supporting tools are used when surveying?
- Metal detectors2. Aerial photography3. Soil restivity4. magnetometer5. Ground penetrating radar6. Cadaver dogs7. Probes8. Stripping
What is the importance of stratigraphic excavation?
- A professional, proactive approach2. Accurate collection of remains and evidence3. Contextual data registration4. Reconstruction of sequence of events
What is the similarity between archaeology and CSI?
Arch: Reconstruction of past events and analysis of physical evidence.CSI: Reconstruction of past events and analysis of physical evidence.
What is stratigraphy?
The analysis of the sequence of deposits in the soil that have formed through natural or human activities.
What is the definition of archaeology?
The documentation by research on the field and by the excavation of the soil. Complete reconstruction of time period & place by the elements.
Define strata
A portion of soil different from the others by shape, colour, composition and hardness.
What is the difference between erosion and destruction?
Erosion - soil moves and accumulates elsewhereDestruction- soil is removed and deposited in a pile elsewhere
What is a stratigraphic unit?
The tangible evidence on the soil left by unique human or natural action.
What is a negative stratigraphic unit?
ONLY A SURFACE. Without volume and content, it is the evidence of destruction (excavation of a grave)
What is relative SU?
The relation between stratigraphic correlations.
What is absolute SU?
Dating according to the elements (artefacts) within.
What should be done if human remains lie on the surface?
- Photograph the scene2. Reconstruct the area of interest.3. Use gridding and mapping to establish spatial control.4. Expose remains with minimal excavation5. Identify the SU6. Collect the exposed remains7. Dig under and near remains8. Sift removed soil
What does the Harris matrix show?
The relative chronology between strata.
What should be done when remains are buried?
- Establish spatial controls2. Remove vegetation and clean area3. Determine area of interest4. Start excavation and determine SU
What should occur during an excavation?
- Take altitude of SU2. Map and take pictures of each SU3. Sift removed soil4. Take soil sample from each SU
Why should a border be left around excavation site? [PICTURE]
In case tool marks are present from offenders digging.
What type of sifting should be used in forensic excavations?
Dry
If there is vegetation growing underneath the corpse, what does this indicate?
Premeditated murder (the grave was open before the body was added).
How should evidence be documented at the scene?
- Progressive ID for each piece of evidence.2. Tag each piece of evidence3. Photograph and map each item before collection.4. Collect each item seperately.
In what direction should documentation of a scene go?
Less invasive to more invasive.Less fragile to more fragile.
What should be done once a piece of evidence has been collected and packaged?
Check the scene again to see if other evidence has come to light.
What type of evidence is placed in large, paper KRAFT bags?
clothes/shoes that need to be dried.
What is a breathable evidence bag?
It allows moisture to escape the bag, but does not allow it to get in.
What type of evidence can be packaged in glass/plastic jars?
Bullets.
What type of containers should guns/knives be packaged in?
Paper boxes/plastic tubes
If tamper-proof tape is not available, how can you ensure it is clear to see if a package has been opened?
Write signature across coloured tape that seals bag.
What is the foam at the bottom of plastic tubes for?
It preserves the blade and prevents compromisation of the container.
When an evidence bag is opened, how should the evidence be re-packaged?
It should be placed in a new evidence bag with the previous bag.
How should an evidence bag be opened?
It should be cut open at the bottom.
What is the benefit of plastic tweezers?
They don’t damage the evidence, metal ones can scratch.
How are fragmented remains reconstructed?
- Acetate sheet placed over the remains2. Pieces drawn on acetate like a jigsaw
What are sterile swabs with tip protectors used for?
Usually DNA samples
What are sterile omni-swabs used for?
Mouth swab
What are self-contained hydration fluid swabs used for?
Dust/pollen collection.
What biohazard risks may be at crime scenes?
- HIV2. HAV, HBV, HCV3. Tetanus
How should excess plaster be removed from a cast?
With hands and water - DO NOT BRUSH (scratching)
What are procedures should the CSO follow?
- No exposed wounds2. Number of CSOs kept to a minimum 3. PPE must be worn4. Not eat/drink/smoke at the scene
What physical risks may crime scenes pose?
- Projectiles (stones etc.)2. Falling3. Electrocution4. Crushing5. Burial6. Respiratory irritation7. Poisoning8. Intoxication9. Explosion10. Fire11. Sunstroke12. Eye irritation13. Acoustic pollution
What does CSO stand for?
Crime scene operator
What does PPE comprise of?
Body: cotton overalls, disposable tyvec suit, PVC apron (lab)Feet: safety footwear, polypropylene overshoesArms: Multiple pairs of glovesRespiratory: Disposable filter with multi-layer seals. (Last thing removed)Head: Goggles, helmetTape: to ensure you are fully sealed with no exposed skin.
What must happen after an investgation?
Authorised personnel must decontaminate the scene.
How is contamination avoided?
- PPE2. Infectious waste disposed of at specific sites.3. Sanitise non-disposable tools
What are the different types of evidence?
- Testimonial2. Documentary 3. Demonstrative4. Physical (pattern & trace)
What are some examples of pattern evidence?
- Fingerprints2. Footprints3. Tyre tracks4. Striation marks5. Handwriting6. Bloodstain7. Powder/pellets8. Char/soot
What is trace evidence?
“Minute bits of physical evidence that may be exchanged among the perpetrator of a crime, the victim and the crime scene.”
Define biological traces.
“Any liquid or solid substance coming from the human body, or which after being in contact with it contains cell remains.”
Give some examples of biological traces
- Blood2. Semen3. Saliva4. Urine5. Hair6. Teeth7. Bone8. Cells/tissues9. Amniotic fluid
On what objects may such traces be found?
- Condoms2. Chewing gum3. Envelopes/stamps4. Paper5. Clothes
What is a reference/standard sample?
Evidence whose origin is known and can be compared to evidence of unknown origin.
What are the stages of investigation of biological traces?
- Sample collection at crime scene2. Packaging, labelling and sending to lab4. Analysis at lab5. Reporting at courtroom.
What are the main components of blood?
- Red cells (erythrocytes)2. White cells (leukocytes)3. Platelets
What is the most common biological evidence?
Blood
Which blood cells contain DNA?
ONLY white
How do we collect reference blood samples?
- Venous puncture - 5ml tube with anticoagulant2. Finger puncture - 3-4 drops. Air dry before packaging.
What is the DNA content of Blood?
30-60 micrograms per microlitre (high)
How do we collect blood traces?
- High amount - Plastic pipette. tube with anticoagulant.2. Small amount - Sterile swab3. Coagulated - plastic spoon
How do we collect traces of blood from objects?
- Small objects - Pack and send to lab2. Big objects: Non-absorbant - Rub with wet swab, scrape off with scalpel.Absorbant - Cut out the stain
What is semen comprised of?
- Spermatozoids (cells) 2. Seminal plasma
What does normal ejaculation contain?
2-6ml of sperm and 100s of millions of cells/ml
How much DNA per sperm cell?
480 micgrams/ml
Is sperm haploid or diploid?
Haploid
How much DNA does saliva contain?
It doesn’t - it is surrounded by epithelial cells which do, bringing DNA content up to 1-10 micrograms/ml (low)
How do we collect reference saliva samples?
- Cheek with a sterile swab2. Taken at least one hour after eating as bacteria degrades DNA3. Left to air dry before packaging.
How much saliva do humans secrete per day?
1-1.5 L
How do we collect saliva traces from objects?
Small objects: Pack and send to labBig objects: Rub with wet swab
What are the components of a tooth?
- Enamel2. Dentin3. Cement4. Dental pulp
What cells make up a tooth?
- Odontoblasts (dentin)2. Cementoblasts (cement)3. Ameloblasts (enamel)4. Osteoblasts (alveolar bone)5. Fibroblasts (Periodontal ligament)
Where does most DNA from a tooth come from?
Dental pulp (blood vessels)
Where are the majority of nucleated cells found in the tooth?
Dental pulp
How else can we obtain DNA from teeth in children?
Dental germs (Less DNA and poorer quality than adults)
What is bone tissue made up of?
- Intercellular matrix (hydroxapatite and collagen)2. Bone cells (osteocytes and osteoblasts)
What are osteocytes and osteoblasts?
Nucleated cells
How many osteocytes/osteoblasts do we find in compact bone?
20000-26000/mm3
What is the DNA content of bone?
3-10ng/mg (very low)
The spleen contains a high amount of nucleated cells, so what is the problem with collecting DNA from here?
It is the first organ to degrade after death, very quickly.
Which bone is most successful for obtaining DNA?
Sternum
Do nails contain DNA?
No - epithelial cells swept along during growth.
What do nails contain?
Keratin (Fibroprotein)
What protein is hair made of?
Keratin
What does the hair shaft contain (cut)?
Mitochondria
When do we collect hair reference samples?
Only when blood/swab sampling is not possible.
What does the hair bulb contain (pulled)?
Nucleated cells
How many hair reference samples do we collect?
10-15 samples with roots.
How do we collect hair traces?
- Sterile forceps2. Package separately3. Use sealing paper bags
What is the meaning of Desquamation?
To shed an outermost layer/membrane
What 6 types of Desquamation cells are there?
Simple/stratified - Squaremous, cuboidal or columnar
Are all Desquamation cells eukaryotic?
Yes
What are the 4 main problems when collecting DNA samples at the crime scene?
- Contamination with biological material2. Transference of biological traces3. Sample degradation 4. Chemical/physical treatments
What is the role of PPE?
To avoid contamination and lower the risk of infection when collecting biological evidence
Why must any biological samples contains DNA be kept in a refrigerator?
The DNA degrades in hot conditions
What is the first type of evidence to be collected?
Biological as it will degrade
Why must gloves be changed frequently?
To avoid cross-contamination
Why must the chain of custody be completed at every step?
A case could be dismissed otherwise
What is the most famous case involving problems with sample collections?
O.J. Simpson
What are the main questions asked in a forensic laboratory?
- Is it biological? If so what is it?2. Is the sample human or not?
What 3 types of tests are run in a forensic lab?
Orientation, confirmatory and specific tests
What is compared in a forensic lab?
Individual characteristics of biological evidence
How is Luminol prepared?
In an alkaline solution with sodium carbonate
How does Luminol work?
Fe^3+ is supplied to the hemo group of haemoglobin
What type of test is Luminol?
Orientation
What two DNA comparisons can be used to identify a victim?
- Relatives2. Other biological samples from the victim
What shows a positive result when using Luminol?
Luminescence of the sample when uv light is applied
How can a perpetrator be identified using DNA ?
- Comparison with suspects 2. Comparison with forensic databases
What is studied in DNA profiling?
Regions of the genome (loci)
Why are loci studied?
- Highly variable in humans2. Low mutation rate3. A standard globally
What is the result of DNA profiling?
Exclusive, individual and unrepeatable DNA profile
What does CODIS stand for?
Combined DNA Index System
How many genome regions have the FBI identified as core loci?
13
How many genomes have both the UK and majority of Europe identified as core loci?
8 +2 that are not on the CODIS system
If a known sample of DNA matches the questioned 13 loci the DNA expert can state that…
Both DNA samples came from the same source
What steps are there to sample DNA analysis?
Extraction - quantitation - profiling - comparison - report results if match found
When are loci found in different places?
In different people
The results of DNA profiling provide a graph with peaks. What does the height refer to?
The amount of DNA in the sample
The results of DNA profiling provide a graph with peaks. What does it mean when the peaks align?
The loci are in the same place proving a match
What is the probability that a given DNA profile matches with a different individual called?
Random match probability
What is the equation for random match probability?
1RMP = ———————————————————– Frequency of the profile in the population (database)
What is CODIS used for?
Linking serial crimes and unsolved cases with repeat offenders
What was CODIS launched?
October 1998
How many states are linked by CODIS?
All 50
What does NDIS stand for?
National DNA Index System
There are over 10 million profiles containing DNA samples from…
Forensic profiling and convicted offenders
What is the UK’s DNA database called?
NDNAD
What does NDNAD stand for?
National DNA Database
How many profiles does NDNAD contains?
6 million
Who are the DNA samples in NDNAD taken from?
Anyone arrested for a recordable offence
A new legislation was passed in parliament in May 2012. What was its aim?
To remove from the database profiles from non convicted offenders
How many genes differentiate between 40 shades of blue and brown (eye colour)?
6
Where can IrisPLEX legally be used as evidence?
The Netherlands
How many genes differentiate hair and eye colour simultaneously?
24 (HIrisPLEX)
What is botany?
The study of the physiology, structure, genetics, ecology and distribution of plants.
What is the importance of plants?
- EVERYWHERE2. Oxygen for life3. Earth’s atmosphere4. Convert solar molecules to complex molecules
How many plant species have been used for food by humans?
7000
How is plant fiber used?
For textiles, rope paper.
How are plants a direct source of food?
We eat them
How are plants an indirect source of food?
We eat animals that eat them.
What fraction of medicines contain materials isolated from plants?
1/4.
How else are plants used in medicine?
Copies of chemicals found in plants are used, or their natural substances are modified.
Define “plant”
Any living thing that cannot move voluntarily, has no sense organs, and generally makes its own food by photosynthesis.
How can plants place a person/object at a crime scene?
- Plants grow i specific areas2. Different areas have different plant profiles3. When plant fragments are found on a person or vehicle, they can be placed in a specific location.
How can plants verify or refute an alibi?
- A suspect may claim to never have visited an area but plant evidence may contradict their claim.2. Evidence from various locations can be combined to show movement (murder site, dump site, storage).
How can plants be used to estimate time since death?
- Growth cycle of plants (different between species)2. Deterioration of plants3. Stomach contents
How can tree rings help verify time since death?
- Number of rings gives age2. Ring width indicates environmental conditions (wider rings - better nutrition - body?)
How can plant wilt help estimate time since death?
- Broken branches wilt2. Amount of wilt can be related to a time-frame3. Experiment - similar branches collected and observed
How can plants help verify crime location?
- Broken branches2. Drag marks on vegetation3. Buried remains4. Site of body deposition.
How can plants help verify grave location?
- Plants grow after soil disturbance (or stunted if body wrapped in plastic)2. Succession of plants is specific to an area3. Localised site at a different successional stage to surrounding areas - potential burial site.
What is the yellowing of grass called?
Chlorosis (insufficient chloropyhll)
While plants can sometimes help identify a place/time of death, they can sometimes ___________
Cause death - poisonousNeed to identify if homicide,accident or suicide
What is the importance of the examination of stomach contents?
- Identify poisons2. Cells from food plants can identify last meal -> identify whereabouts3. Time since death can be estimated from state of digestion.
Digestion in the mouth takes ____
1 sec-2 mins
Digestion in the stomach takes _____
2-6hrs
How long does digestion in the small intestine take?
2-8hrs
How long does digestion in the large intestine take?
6-9hrs
Total digestion time in humans is ___
10-23hrs
Give 3 examples of controlled substances derived from plants:
Marijuana, opium poppy, peyote
The study of pollen grains is called___
Pallynology
How is Pallynology useful in forensics?
It provides links between people and places.
What is pollen rain?
The expected production and dispersal patterns of spores and pollen for any given area.
What are the three types of pollination?
- Self-pollinating (up to 100 grains)2. Animal pollinating3. Wind pollinating (up to 70,000 grains)
Give details of the Bosnia mass graves pollen case study.
- Kill site and primary graves2. Remains exhumed and moved to secondary graves3. Pollen and soil provided “environmental profile” of primary site
When did autopsies begin?
Around 3000BC in Ancient Egypt - embalming
Who is the father of modern pathology?
Rudolph Virchow
What did Burke and Hare do?
- Killed several tenants of Hare’s2. Sold bodies for £8-10 to medical school3. Hare testified and Burke was hanged in 1829
When was body donation allowed?
1832
How is the autopsy utilised?
- Medical education2. Evaluate treatment3. Identify new diseases4. Clarify mechanisms/patterns of illness5. Explore treatments
What are the differences between forensic and hospital autopsies?
Forensic - permission by law, complete, forensic pathologist, no cost to survivors.Hospital - Next-of-kin permission, may be partial, hospital pathologist, may be added to medical charges.
What are the objectives of the forensic autopsy?
- Establish cause of death2. Establish manner of death3. Estimate time of death/injury4. Collect evidence5. ID deceased
What manners of death are there?
- Natural2. Accident3. Suicide4. homicide5. Undetermined
What is cause of death?
How the death occured (e.g bled out)
What are common concerns about autopsies?
- Disfiguring remains2. Delay of funeral3. Religious objections4. Deceased did not want one5. Family refuse6. Cost (hospital)
No autopsy is required when_____
- Terminal event witnessed or readily acceptable2. No controversy over cause or manner of death3. No civil or criminal litigation anticipated (no need for court)4. External exam not remarkable
What can be used to reduce the need for a complete autopsy amid religious objections?
- Detailed scene investigation, past social and medical history.2. Exclusion of criminal involvement3. External exam4. Radiographs (foreign objects)5. Toxicology6. Partial autopsies
What do we look for in an autopsy?
- Anything and everything - abnormal development?2. Any evidence of natural disease3. Any evidence of injury
What does a forensic autopsy entail?
- Photographs, x-rays2. Examination of clothing3. External examination4. Internal examination5. Evidence collection6. Tissue sampling for histology7. Fingerprints8. Anthropology and odontology exam if indicated.
How does an internal examination begin?
with a I or Y incision.
Common mistakes in forensic pathology include___
- Being unaware of the objectives of a medico-legal autopsy2. Incomplete autopsy3. Embalming permitted4. Regarding mutilated/decomposing body unsuitable for autopsy5. Not recognising post-mortem changes6. Failing to make adequate external exam7. Missing bruises on dark skin8. Body not examined at scene9. Inadequate photography
Why do we photograph?
- Tell story2. Capture the scene in current state3. Use in court4. To show we have not hidden anything5. Aid memory6. Support notes7. Evidence can be lost or destroyed
What is the literal definition of photography?
“write with light”
What do we aim for with photography?
A well lit, clear and focussed photograph.
Questions to ask when composing a photograph____
- What is our primary subject/scene?2. What is important to see?3. What is in the background - is it relevent?
What things must be considered when composing a photograph?
- Angles2. Lighting3. All 4 corners4. Reflections5. Omit irrelevence
What type of scene photographs should be taken?
- Overall - identifying location2. Mid-range3. Close ups with and without scale if relevent4. All photos need to link
How do we avoid flash reflection?
Take the photo at a slight diagonal.
How do you compose a photo?
- Fill frame2. Focus3. Depth of field
What subjects may require the use of macro photography?
- Fingerprints2. Hair3. Nails4. Insects5. Bullets6. Engravings
What is the focal length of a wide-angle lens?
18mm
What is used to control exposure?
- Aperture2. Shutter speed3. Film speed/ISO4. Lighting
What is aperture?
The size of the hole that lets light in (f-stop or f-number)Smaller no. - larger aperture
What depth of field is best for crime scene work?
f8-16
What can long exposures be useful for in forensic photography?
Blood enhancement.
What is needed for night scenes?
- Tripod2. Torch/headlights3. Cable release4. Long shutter speed5. Wireless external flash
What is the shutter speed?
The time that the shutter is open, it determines how much light gets to the sensor.
If the shutter speed is less than 1/125, what is needed?
A tripod
What does ISO stand for?
International Organisation for Standardisation.
What ISO should be used for inside photography?
400
What ISO should be used for sunny days and evidence quality?
100
How should vehicles be photographed?
- Rear and front 3/42. Use fill in flash for shadows and dents3. VIN4. Tax disc5. Number plate6. Outside to inside
4 rules about image manipulation____
- Do not make changes to originals2. If a photo is cropped, the original must be disclosed3. Never delete a poor image4. If the photo is poor quality, no amount of manipulation will help.
How to fill out photo logs____
- Photo number2. Description of photo3. Time taken
In mass fatality cases we need to _________
Collect lots of evidence in a short time
Why is the black box located at the rear of an aircraft?
It is more likely to survive an impact, so that data can be retrieved.
What path does an explosion follow?
The path of least resistance.
What is deflagration?
subsonic combustion - less than the speed of sound.
What is detonation?
Supersonic, exothermic front acceleration - faster than speed of sound.
After explosion, air continues to ___ before ____ again
fall, rising
What are the 5 stages of an explosion?
- Moment 02. Positive phase (compression phase)3. max. expansion4. Negative phase (suction)5. end
What are the primary injuries from the pressure of a blast?
ears, gastrointestinal tract, lungs
What causes secondary blast injuries?
Projectiles (shrapnel effect)
what causes tertiary blast injuries?
Impact against surfaces
How is a low explosive ignited?
By flame
Black powder is a low explosive, at what speed does it travel?
1300 fps (feet per second)
What are two other examples of low explosive and how fast do they travel?
smokeless powder and flash powder - 2500fps
How are high explosives ignited?
Detonation.
How sensitive is a primary high explosive?
Extremely sensitive.
How sensitive is a secondary high explosive?
Relatively insensitive.
How fast do high explosives travel?
11/20,000fps
Are low explosives subsonic or supersonic?
Subsonic - deflagration
Are high explosives subsonic or supersonic?
supersonic - detonation
Define deflagration:
combustion which propagates through a gas or across the surface of an explosive at subsonic speeds, driven by the transfer of heat.
The outdoor evacuation distance for explosives is also the _____
radius of the crime scene.
How is a planned search carried out?
- Establish a baseling N/S2. Aisles and transepts3. Professional search for forensic evidence4. Non-expert search for associated/related materials.
What do we need to determine from debris?
Cause and manner
What do we need to determine from human remains?
Identification and dynamics
What do we need to determine from the environmental impact of a crash?
The dynamics of the crash.
Which explosive evidence must be collected by qualified personnel?
components and human remains
Which explosive evidence can be collected by non-professional staff?
Distribution of elements and unidentifiable materials.
What does DMORT stand for?
Disaster Mortuary Operational Response Team.
What is DMORT?
A team of experts in victim identification and mortuary services that responds to large scale disasters in the US.
What comprises a temporary morgue?
A pathology station, a photography station and a radiology station.
What occurs at a forensic anatomy station?
- Sorting and assembling2. Biological profile3. ante mortem (AM) data collection
What occurs at a forensic anatomy station?
Conservation state analysis
What occurs at a trauma analysis station?
Description and sequencing of trauma
What is the role of a forensic anthropologist at the scene?
- Sort fragments2. Document
What is the role of a forensic anthropologist in the morgue?
- Triage activity2. Identification
Who works in triage?
Anthropologist, pathologist, odontologist, DNA expert, CSO
What takes place in triage?
- Decide whether human or non-human2. Decide whether pieces of structures or objects3. Deliver to specific morgue’s section
What makes up the biological profile?
- Age2. Sex3. Ancestry4. Stature
What order should things occur at the scene?
- Survey2. Pin flagging3. Mapping & coding4. Photography5. Collecting
What is Cellmark?
The major forensic science provider in the UK.
What period is the most critical time in an investigation?
The first 30 minutes.
What is the first priority before anything else?
Making the scene safe.
What two things are useful in aiding an investigation?
CCTV and witnesses.
What does MIR stand for?
Major Incident Room.
What the responsibilities of the major incident room?
- Accurately record info, enquiries made results obtained.2. Establish whether a person is known to the enquiry previously, or whether an enquiry has been previously made.3. Historical reference/database.4. Recording & linking info to be easily retrieved.
What does SIO stand for?
Senior Investigating Officer.
What ranks of police can be an SIO?
DI, DCI, DSupt
What is the role of an SIO?
- Team leader with working knowledge of the murder investigation manual2. Provide investigative focus3. Coordinate & motivate team4. Accountable for every facet of enquiry
What is the role of an exhibits officer?
- Record all items retrieved in a secure location2. Each item is considered for its evidential value.3. HOLMES2 4. Document management5. Task management
What does HOLMES stand for?
Home Office Large Major Enquiry System
What is the role of the budget holder?
Authorises sending things for testing etc.
Ensure the cordon is ________
Appropriate (Can’t be extended).
What is essential to be completed throughout the investigation?
Scene log
What must be observed at the scene?
- Presence of obvious evidence.2. Boundaries - fences etc.3. Area where evidence can be reasonably linked to offence.
What evidence from a crime scene is least trustworthy?
Witness statements.
What comprises a scene log?
When, where, what, sketch, details of who enters scene & why and when in & out.
When examining the outer scene, what must be done?
Preserve and record any evidence.
When assessing the scene, what must be done?
Ensure all evidence has been collected.
What evidence must be collected first?
Vulnerable.
What does NABIS stand for?
National Ballistics Intelligence Service
What is used when searching for cadavers?
- Aerial photography2. Cadaver dogs3. Search patterns
What type of photography is used during an excavation?
Time-lapse
What can be used to discount alibis?
Cell site analysis.
Why should wooden instruments be used in a post-mortem?
To avoid damage to the bones.
What did the supreme court used to be?
The house of Lords.
Civil court matters are usually settled by ____
Payment of money (rarely imprisonment).
Where are most civil matters settled?
County court, but can also be heard in magistrates court.
What is a claimant?
The person bringing the case.
What is a defendant?
The person the case is against.
Big cases involving lots of money can be heard in ___
The high court.
What is the limit for small claims courts?
£5000
Who has the ultimate authority on European law?
European court of justice.
Where is the European court of justice based?
Luxembourg
When did the European Court of Human Rights arise?
1950 from the European convention on human rights.
Name the first 7 articles of human rights.
- Respecting rights2. Right to life3. Right not to suffer torture/inhumane treatment4. Prohibits slavery or forced labour5. Right to liberty6. Right to a fair legal hearing & presumtion of innocence.7. Right to legal certainty and no retrospective punishment.
Name the last 7 articles of human rights.
- Right to private life9. Right to freedom of thought, conscience and religion.10. Right to freedom of expression.11. Right to freedom of assembly12. Right to marry13. Right for an effective remedy14. Right to be free from discrimination.
The ____ prosecutes on behalf of the public
Crown
What is a felony?
A serious crime such as theft.
What is a misdemeanor?
A less serious crime like driving offences or drunk and disorderly.
What are the three categories of offences?
Summary, Indictable and either way.
Where are summary offences tried?
Magistrates (up to 2 yr sentences)
Where are indictable tried?
Crown Court and have a committal hearing.
Where are either way offences tried?
Magistrates usually but can elect for a jury trail at crown court.
Where do cases start?
Magistrates court.
What is the minimum sentence from a magistrates court?
5 days.
What is the maximum sentence from a magistrates court?
6 months for 1 offence, 12 months for 2.
What characterises youth courts?
- Under 18s2. Less formal3. Circular table
When was the crown court created?
1971.
Treason and murder are examples of what class of offence?
Class 1.
What offences are class 2 offences?
Manslaughter and rape.
Who are class 1 offences heard by?
High court judge.
Who are class 2 offences heard by?
Circuit judge.
What offences are class 3 offences?
Kidnapping, burglary, GBH, robbery.
Who are class 3 offences heard by?
A circuit judge or recorder.
When was the supreme court established?
1st October 2009.
What does a legal clerk do?
Inform magistrates of law and sentences available.
What does an usher do?
Ensures courtroom is ready, bring in witnesses, control courtroom.
How many lay magistrates are there?
3
How to address a magistrate
Your worship, sir or madam
How to address circuit judges
Your honour
How do you address a high court judge?
Honourable or right honourable, my lord/my lady.
What did common law evolve from?
The beginings of society.
What is a crime?
An act or ommission which contravenes the law and which may be followed by prosecution.
What is the aim of punishment?
To defer from recidivism/ remove from society for protection.
Common laws came from secular courts in ____
1150s.
Who is statute law made by?
Parliament.
Where does the first reading of the bill occur?
House of commons.
The judge/magistrate decides on the ____withing parameters.
Sentence.
The home secretary cannot alter the ___
Minimum tariff.
What does discharge mean?
Completely let off.
What is the maximum fine that can be given by the crown court?
Unlimited.
What is the maximum fine for a 14-17 year old?
£1000.
What does a community sentence include?
Community work, curfew, exclusion order, reparation, ASBOs.
Young offenders institutions are for ages _____
18-21.
Legal defences include____
provocation, duress, necessity, insanity
All new criminal offences must be created by ____
statute law
When primary legislation is ambiguous ____
the court may refer to statements from House(s).
What is the golden rule of criminal law?
Ordinary sense of a word is adhered to unless it leads to absurdity.
In order to be found guilty of a crime, you need to have 2 elements present: ____
Mens Rea and Actus Reus
What is the literal meaning of Actus Reus?
“Guilty act”
What is the literal meaning of Mens rea?
“Guilty mind”
In order to posses Actus Reus and Mens Rea, what characteristics would a person demonstrate?
- Behaving in a certain way2. Having a certain attitude
What exceptions are there to Mens Rea and Actus Reus?
Crimes of strict liability.
What must each definition of common law and statute law contain?
Mens Rea and Actus Reus.
To what extent must an offence be proved for sentencing to take place?
‘Beyond reasonable doubt’
How is a defendant treated?
Innocent until proven guilty.
What does a guilty act involve?
- Intent2. Circumstances of the offence3. Consequences of the offence.
How can you prove rape?
- Show unlawful sexual intercourse without consent.2. Lack of consent is a surrounding circumstance that exists independantly of the act itself.
How can actus reus be the same for different offences?
Different consequences of same act. E.g stabbing -> Murder or GBH if die or survive.
What are the 4 types of crime?
- Action crimes2. State of affairs crime3. Result crimes4. Ommision crimes
What is an action crime?
A crime in which the consequences are immaterial.
Give an example of an action crime.
Lying under oath -> Result is immaterial to decide whether perjury has occurred.
What is a state of affairs crime?
circumstances, sometimes consequences but not acts.
Give an example of a state of affairs crime.
Found in Britain without having permission to be here.
What is a result crime?
The accused behaviour must produce a certain result.
Give an example of a result crime.
Murder - leads to a persons death.
What is an omission crime?
A failure to act. (continuing acts, supervening faults)
Give an example of a continuing act (omission crime)
Rape - consent is withdrawn but act continues.
Give an example of a supervening fault (omission crime).
Endangering someone’s life and failing to prevent harm.
What type of crime is euthanasia an example of?
Omission crime.
Mens rea has nothing to with ____
motive.
What types of mens rea are there?
- Intention2. Recklessness3. Negligence4. Transferred malice
What is intention as part of mens rea?
- What the defendant intended from the offence.2. Not what a reasonable person would have intended3. Direct - decide to bring certain consequence4. Indirect - Don’t mean consequence but know it will probably happen. Jury decides if intent was present.
What is negligence as part of mens rea?
- ‘Standard duty of care’2. Defendants conduct falls below standards of reasonable person.3. Rare4. Used in statutory offences (e.g. motoring).
What is recklessness as part of mens rea?
- Unjustified risk taking which causes damage/harm2. Subjective - was risk forseen by defendant but continue anyway?3. Objective - Would a reasonable person have forseen the risk?
What is transferred malice as part of mens rea?
Victim was not the intended target.
With strict liability, ____ does not have to be proven if ___ is proved.
Mens rea, actus reus.If you commit a guilty act, it doesn’t matter whether you meant to or not, YOU DID.
Who is the principle offender?
The person who commits the AR.
Who are the secondary parties?
People who aid the commission of an offence.
In order for secondary parties to recieve same punishment at principle offender, what must be proved?
- They intended to assist the TYPE of crime2. The act stopped at an agreed point
What categories of homicide are there?
- Murder2. Voluntary manslaughter3. Involuntary manslaughter
What type of offence is murder?
Common law offence.
What is the definition of murder?
The unlawful killing of a human being with malice aforethought (premeditation).
What is the MR of murder?
An intention to kill or cause grievous bodily harm.
What is the AR of murder?
The murderer must be of sound mind and age of discretion.
What must be proved for a sentence of murder?
Causation factually and legally.Factual - victim would not have died without defendants conduct.Legal - sufficient law to amount to cause of death.
Does voluntary manslaughter have MR and AR for murder?
yes.
What examples of mitigating circumstances for voluntary manslaughter are there?
Provocation, diminished responsibility.
What argument for provocation can reduce a sentence for VM?
A reasonable man would have been so provoked and lost control.
What must be present for diminished responsibility to be claimed?
Abnormality of the mind which impairs mental responsibility for acts or omissions.
In a case of involuntary manslaughter, ____ exists but _____ doesn’t.
Actus reus, mens rea.
What is constructive manslaughter?
A type of involuntary manslaughter in which the act leading to death was unlawful and dangerous.
What is gross negligence manslaughter?
A type of involuntary manslaughter in which breaching duty of care leads to death, but an illegal act has not necessarily been committed.
What is the actus reus of rape?
Sexual intercourse without consent.
What is the mens rea of rape?
Knowing the victim did not consent or is reckless as to whether there is consent.
What is theft?
The dishonest appropriation of property belonging to another with the intention of permanently depriving the other of it.
What is the actus reus of theft?
Property appropraition belonging to another.
What is the mens rea of theft?
Intention to permanently deprive. Dishonesty.
What is burglary?
Entering a building as a trespasser with intent to commit theft, GBH, rape or criminal damage.
What is the actus reus of burglary?
Trespass/entry of a building or part of building.
What is the mens rea of burglary?
Intention or recklessness as to the trespass.Intention to commit ulterior offence.
What is robbery?
Stealing and immediately before or at the time, using force on any person or puts/seeks to put a person in fear of force.THEFT + FORCE (or threat of force)
What is the actus reus of robbery?
Theft with force or threat of force. Property appropriation from another.
What is the mens rea of robbery?
Intention to permanently deprive.Dishonesty.
A complete defence may result in ___
Acquittal
A partial defence may result in ____
conviction for a lesser offence - diminished responsibility.
What is the burden of proof?
The duty to prove or disprove a disputed act.
The defence burden of proof must prove____
- Necessity2. Reasonable force.
What is public defence?
Defence taken to protect the public - reasonable force/ arrest.
What is private defence?
Self-defence (recognised by common law).
What is the minimum age of conviction?
10
What is automatism
Performance of actions without concious thought. (may be caused by a knock to the head, may not be used if self-inflicted e.g drugs/alcohol)
If the offence was a mistake, ____ may not be present.
mens rea.
How can duress be used as a defence?
Compelled to act out of fear - would a reasonable person have responded in the same way?
Can intoxication be used as a defence?
Not if mens rea exists.
What is the literal meaning of Forensic Taphonomy?
Laws of burial
What is forensic Taphonomy the study of?
Processes and changes that occur between the time of a persons death and the time of the body’s discovery
What evidence is there for Taphonomy?
Palaeontology - rock and fossil records
What is the difference between forensic Taphonomy and forensic autopsy?
Taphonomy deals with the scene and autopsy deals with the body
What are the goals of forensic Taphonomy?
- Estimation of time since death
- Reconstruction of per imported period
- Discriminate between changes produced by human behaviour from those created by natural processes
What are extrinsic factors?
Variables originating from outside the body or individual
What example of extrinsic factors are there?
- Deposition environment (buria, surface, water)
- Climate (temperature, sun, humidity)
- Exposure to animals (scavenging)
- Insects
What is an intrinsic factor?
Variables originating from within the body or individual
What examples of intrinsic factors exist?
- Body size
- Per imported trauma
- Clothing/covering
- Per imported modifications
Why might not all elements survive/be recovered?
Transport/dispersal or differential presentation
Why is investigator bias important?
It can make or break a case if it compromises evidence
What must be perfected to avoid investigator bias?
Recovery perception, collection methods, transportation, curation and analysis
What does recovery of the body impact?
How much you get, how much you see and how you interpret
What are the two types of modification?
Artefact and eco fact
What is an artifact?
- By-product of human action
- Either direct or indirect
- Any modification or trace
What is an ecofact?
By-product of modification resulting from natural processes
What are the 5 stages of decomposition?
Fresh - bloating - active - advanced - skeletal
How long does the fresh period last?
From actual death until the first signs of bloating
What characterises the fresh stage?
A decrease in body temperature over time, no odour
What is the end stage hallmark of the fresh stage?
The arrival of blow flies and subsequent deposition of eggs
What marks the beginning of the bloat stage?
Bloated appearance with distended abdomen marks the
What is characteristic of the bloat stage?
Discolouration, marbling, strong odour and extruded organs
What marks the end of the bloating stage?
Development of maggot mass
