M3 Flashcards
Sexual Assault Nurse Examiners (SANE)
A specially trained individual that performs the medical examination of complaints in sexual assault cases
Sexual Assault Response Team (SART)
Forensic nurses take a lead role in the coordinated response by the
sexual assault evidence collection kit (“rape kit”)
Complainants are take to a medical facility or a SANE/SART facility to attend to their medical needs and to collect relevant evidence using a
The Forensic Scientist’s Role
*Sexual assualt evidence collection kits are forwarded to the forensic lab for examination
*The forensic scientist’s primary role is the analysis of the physical evidence.
*If semen is present it helps to establish the corpus delicti
*If semen or other fluids are found, DNA typing is conducted to determine if there is a match to suspect or an exclusion.
3 types of sexual assault cases
1 Unknown offender (identification cases),
2 Known offender (consent cases), and
3 Sexual assaults involving children
Other forms of evidence that are important to consider
drug-facilitated sexual assault (DFSA)
Impression analysis of latent prints
Digital or other multimedia analysis
Chemical analysis of swabs
Fabric separation analysis of clothing
Firearms analysis of clothing for muzzle-to-target distance determination
Drug Facilitated Sexual Assault
*“date rape” drugs: rohypnol, GHB, ketamine
*All are depressants with amnestic effects, and are often used along with alcohol.
*These types of cases require toxicological analysis of the evidence.
Recommended to collect the following samples:
- Peri-oral area, lips, and oral cavity
- Posterior fornix and cervix (in the post pubertal female)
- Peri-anal folds, anus, and rectum
- External anogenital structures (male or female)
- Neck
- Breasts
- Palm of hands
- Fingernails
Sample Collection
Oral sample, external genital sample, vaginal/cervical sample, penile sample, perineal sample, anal/rectal sample
Wet-mount evaluation
*Some jurisdictions require examiners to conduct wet-mount examinations of vaginal/cervix secretions for motile and nonmotile sperm in cases in which a male suspect may have ejaculated in a patient’s vagina
*Because sperm motility decreases quickly with time and removal from the vagina/cervix, wet-mount evaluation during the exam can provide the only opportunity to see sperm motility.
*The presence of motile sperm may help narrow the timeframe that the crime could have occurred.
Slides and Smears:
*Creating slides and smears at the medical exam site from oral and anogenital samples is UNNECESSARY and should be elminated, since the slides prepared during the medical exam generally have more epithelial cells, bacteria, and other debris.
Suspect Sample Collection
*Expect for the routine reference sample collection (usually in the form of a buccal swab), a full medical-forensic examination or other suspect sample collection should ideally be completed by a medical-forensic examiner or appropriately trained individual.
*collected from a suspect by law enforcement personnel in accordance with a lawful court order.
Semen Function
*Lubricates sperm duct/urethra
*Nutritive and protective liquid medium for sperm to travel in.
*Alkaline environment which protects the sperm against the acidic nature of the vaginal tract.
Semen components originate form several sources
Seminal vesicle fluid
Prostatic fluid secretions
Epididymis and bulbourethral glands
What could affect how many Spermatozoa per ejaculation?
- Medical conditions
- Genetic background
- Diet
- Smoking
- Illicit drug use
- radiation
- environmental toxins
- undescended testis
- varicocele
- trauma
- Aging
- Skinny jeans (?!)
Oligospermia
abnormally low sperm count
Aspermia
no sperm
Pre-ejaculation fluid
*Originates from bulburethral gland (also known as cowpers gland).
*Functions as a natural lubricant during intercourse
*If there is absence of full male ejaculation, this fluid could have forensic significance.
*Widely accepted it contains traces of acid phophatase and prostate specific antigen; no evidence to date of the presence of semenogeliln.
Parts of Sperm Cells/Spermatazoa
1 Head
2 Middle Piece/neck
3 Tail
Why is semen important in an investigation?
- Evidence in sexual assault cases
- Can help prove a crime was committed
- Can identify the perpetrator
Semen Visual Search
i White light
ii Alternate Light Source (ALS)
iii UVA Light (Woods Lamp Technique)
Semen Acid Phophatase (AP)
Acid phosphatases are a class of enzymes found in various living tissues
*Mammalian liver to cauliflower stem juice
*Diseases of the bone, such as Paget’s disease or hyperparathyroidism, diseases of blood cells, such as sickle-cell disease or multiple myeloma or lysosomal storage diseases, such as Gaucher’s disease, will show moderately increased levels
*Breast milk, urine, and vaginal secretions
i Spot Test
Purple
PAP
Semen contains very high levels of prostatic acid phosphatase (PAP)
*PAP is an enzyme secreted by the epithelia cells of the prostate gland
*High levels of PAP in blood may indicate prostate cancer
*Its level proportionally increases with prostate cancer progression
*AP levels in semen not affected by vasectomies
Spot and Mapping test
Acid Phophatase Test (AP) Spot Test
- Brentamine Fast Blue B Test
- Will react with semen diluted 500-fold
- Another rapid color change test
- by far the most commonly used
- First introduced in 1957 by Stuart Kind
Positive reaction is purple
