Topic 2 Flashcards
- this refers to a relationship to a court of justice and legal proceeding.
Forensic
– this refers to branch of science that deals with the identification of the substances of which matter is composed.
Chemistry
– this refers to the branch of chemistry that deals with the application of chemical principles in the solution of problems that arise in connection with the administration of justice.
Forensic Chemistry
– Police is usually inclined to be niggardly (not generous) in taking samples. This mistake should be avoided.
Sufficiency of the specimen
– If the evidence in question is found in the presence of foreign substance, a sample of the foreign substance must be submitted for analysis.
Standard for comparison
– Each evidence must be collected and preserved as a separate sample. There must be no mixing or intermingling of unknown to known.
Maintenance of Individuality
– Evidence will have no value in court in spite of the good report of the expert if the specimen cannot be identified and possibility of tampering excluded.
Labeling and Sealing
– the first step in the examination of an article is to scrutinize it carefully and write down the laboratory notebook a complete description of its external appearance including the manner in which it is secured and particulars of the sealing.
ACTUAL EXAMINATION OF SPECIMEN
– the results of the examination conducted will be communicated to the requesting party in the form of a written report which must include an enumeration of the articles received for examination with detailed description of the packing, sealing and labeling date of receipt and from whom receive the purpose of the examination, the findings and conclusion. T
COMMUNICATION OF RESULTS
– the written report of the chemist is usually supplemented at a later date by oral evidence if the case is brought to court or fiscal’s office. In court appearance the witness must be composed and as much as possible avoid being irritated by upbraiding of the opposite counsel.
COURT APPEARANCES
– Good work cannot be buried, therefore take all the time necessary to make the case complete, no matter how urgent it may appear or how pressing others may be of the results; it is generally possible to adjourn a case if the work cannot be finished in time.
Go Slowly
– Make a careful and minute examination of everything and do not be satisfied with a qualitative analysis if a quantitative one be possible; it always pays to do too much rather than to little and it is difficult to foresee what will or will not be requires in court.
Be thorough
- Keep a full, neat and clear record of everything seen and done.
Take notes
– Many cases will lead the expert into paths with which he is not familiar, and when this happens he should consult others who are most likely to know.
Consult others
– it enables and deduction to be made from slender and incomplete premise is very useful.
Use imagination
– the simplest explanation is usually the right one.
Avoid complicated theories
– Requires much time and effort
Wet Method
– this refers to the utilization of UV and IR Spectrophometry.
High Precision Method
– this refers to the technical field of using microscope to view samples and object that cannot be seen with the unaided eye (objects that are not within the resolution range of the normal eye).
Microscopy
– (Preservation of evidence) this refers to the study concerning the duplication of images through the action of light, upon sensitized materials (photographic paper or film) with the aid of mechanical device (camera) and its accessories and the chemical processes (film developing and printing) involved therein.
Photography
– this refers to the use of invisible spectrum of light such as UV, IR, X-ray and etc. for the identification and evaluation of pieces of evidence.
Invisible Rays
– this refers to biophysical techniques that enables the separation, identification and purification of the component of a mixture for qualitative and quantitative analysis.
Chromatography
– this refers to laboratory technique used to separate DNA, RNA or protein molecules based on their size and electrical charge. An electric current is use to move molecules to be separated through a gel. Pores in the gel work like a sieve, allowing smaller molecules to move faster than larger molecules.
Electrophoresis
– this refers to the technique of using spectrograph, an optical device for breaking the light down into a spectrum and recording the results photographically.
Spectrography
– this refers to a nuclear process used for determining the concentrations of elements in a vast amount of materials. NAA relies on excitation by neutrons so that the treated sample emits gamma – rays. It allows the precise identification and quantification of the elements above all of the trace element in the sample.
Neutron Activation Analysis
– this refers to a rapid analytical technique primarily used for phase identification of a crystalline material and can provide information on unit cell dimensions. The analyzed material is finely ground, homogenized and average bulk composition is determined.
XRD (X-ray Diffraction)
– this refers to a laboratory procedure that detects normal variation in a sample of DNA (deoxyribonucleic acid). DNA typing is most often used to establish identity, parentage, family relationship and appropriate matches for transplantation of organs and tissues.
DNA Typing (DNA Profiling)
– this refers to the study of investigation/anthropods in criminal investigation. Right from the early stages insects are attracted to the decomposing body and may lay eggs in it. By studying the insect population and the developing larval stages, forensic scientist can estimate the postmortem index, any change in position of the corpse as well as the cause of death.
Forensic Entomology
this refers to an analytical technique that measures the concentration of element. Atomic absorption is so sensitive that it can measure down to parts per billion of a gram in a sample. The technique make use of wavelengths of light specially absorbed by an element.
Atomic Absorption Spectrometry (AAS) –
– this scientific equipment is used for the qualitative and quantitative determination of volatile or non-volatile compound based on the chromatographic separation of its components.
HPLC (High Powered Liquid Chromatography)
- it is used for the qualitative and quantitative analysis of organic compounds.
EMIT (Enzyme Multiple Immuno Assay
Ultra-Violet Spectrophotometer
– it is used for screening of abused urine samples.
Technique)
– this scientific equipment is used for the physical identification of various questioned specimens. It is a software-controlled digital scanning electron microscope used to produce sticking images over a wide range of magnification (3x3,000,000x) ori rough or covered surface of minute specimen such as hair, fibers, paint particles, drugs metals, etc.
SEM (Scanning Electron Microscope)
– Used for the identification of pure organic substances. It identifies organic substances particularly abused drugs and explosive ingredients based on their characteristic functional groups. In layman’s term, the resulting fingerprints of the substance.
FTIR (Fourier Transform Infrared Spectroscopy)
– Used for the identification of pure organic substances. It identifies organic substances particularly abused drugs and explosive ingredients based on their characteristic functional groups. In layman’s term, the resulting fingerprints of the substance.
FTIR (Fourier Transform Infrared Spectroscopy)
– talks about the action
Sensitivity
– talks about its individuality
Specificity
– talks about the reaction of time
Rapidity
– every object, natural or man-made has an individuality which is not duplicated in any other object
Law of Individuality
- everything changes with the passage of time
Law of Progressive Change
– only “likes” can be compared
Principle of Comparison
– analysis of two or more sets to understand any difference.
Principle of Analysis
- all identification, definite or indefinite are made consciously or unconsciously on the basis of probability
Law of Probability
– any physical location in which a crime has occurred or is suspected of having occurred.
Crime Scene
– the original of the crime or accident
Primary Crime Scene
– an alternated location such as where the additional evidence may be found.
Secondary Crime Scene
– person thought to be capable of committing a crime.
Suspect
– second person associated with committing a crime.
Accomplice
- statement of where a suspect was at the time of a crime
Alibi
– is a means, sanction by law of ascertaining in a judicial proceeding the truth respecting a matter of fact.
Evidence
– would be any witnessed accounts of an incident or crime
Testimonial Evidence
– any material items that would be present on the crime scene or the victims. Presented in a crime investigation to prove or disprove the facts of the issue. Eg, DNA, Body Itself, Weapon used. Pieces of carpet, blood and ther body fluids, Fingerprint or casts of footprints or tire print and etc.
Physical Evidence
– refers evidence that is found at a crime scene in a small but measurable amounts.
Trace Evidence
– Evidence which is addressed to the senses of the court.
Real or Autoptic Evidence
– Comes from people eg. Testimony of an expert witness in court
Testimonial Evidence
- an expert witness may be required to perform certain experiment to prove a certain matter of fact.
Experimental Evidence
- any written evidence presented by an expert witness in court.
Documentary Evidence
– that which the senses perceive. Any fact to which a witness testifies based on what he saw, heard, smelled, touched or tasted.
Direct Evidence
– a kind of evidence which seeks to establish a conclusion by inferences from proved facts. An evidence which establishes a fact or circumstances from which the court may infer another fact at issue.
Circumstantial Evidence
- a statement made by a witness on the authority of another and not from his own personal knowledge or observation. Hearsay evidence is inadmissible except with certain well – defined exceptions. Some of the common exceptions to the rules of exclusion generally applicable to hearsay evidence are declaration against interest, dying declaration, res gestae, public records and statement made at a prior time.
Hearsay Evidence
-One who testifies in court and has personal knowledge or experience of something. A person other that the suspect who is requested to give information concerning an incident or person. He may be a victim, a complainant, an accuser. A source of information, and an observer of an occurrence. A witness in court may be an ordinary or expert witness.
Witness
– it refers to one who states facts and may not express his opinions or conclusion.
Ordinary Witness
– this refers to one who possesses a special skill, be it in art, trade or science or one who has special skill, be it in art, trade or science or one who has special knowledge in matters not generally known to men or ordinary education and experience. He is a person skilled in some art, trade or science to the extent that he possesses information not within the common knowledge of man.
Expert Witness
