Forensics method validated for sexual assault cases

August 7, 2014 by Kerry Faulkner, Science Network WA
Early evidence kits are self-administered and are precursors to full forensic testing at a hospital. Credit: Debbie Smith, Sexual Assault Resource Centre

The importance of urine in capturing vital evidence of sperm and DNA in sexual assault cases has been proven by WA researchers.

WA Police Sexual Assault Squad, PathWest forensic biologists and Sexual Assault Resource Centre (SARC) doctors collaborated on the research that investigated 100 consecutive alleged rape cases in Western Australia over four years.

Detective Senior Sergeant Stephen Foley says it's imperative police reduce the risk of losing evidence like sperm and DNA after an attack, which can happen when victims wash or urinate.

To capture this evidence, victims are asked to self-administer a series of non-invasive tests from an early evidence kit consisting of swabs and samples, including urine and saliva samples.

The kit is a precursor to full forensic testing at a hospital that can occur hours after the attack, particularly in remote locations.

SARC's Debbie Smith says from their research, Western Australia appears to be the only laboratory in the world that tests urine not only for toxicology (drugs and alcohol), but also for spermatozoa and DNA material.

She says the research highlights for the first time the importance of this urine sample for capturing forensic evidence.

"In the penile-vaginal sexual assault we could see early evidence kits were useful in picking up sperm and in particular urine was an important specimen to collect, coupled with a gauze wipe of the vulva," Dr Smith says.

"Sperm was detected in the early evidence kit in 40 per cent of cases of alleged penile-vaginal when both a and a vulval gauze wipe were collected."

PathWest forensic biologist Laurance Webb says scientists target any cellular material in the samples. They decant off the liquid, swabbing a pellet of residual cells to test for DNA material. A smear of the same cellular material is then used to identify any spermatozoa that may be in the sample.

SARC's Maureen Phillips says in some instances early evidence kit specimens captured sperm and DNA that under full-forensic examination tested negative.

"Sperm doesn't last forever on the body; around the mouth it can last only a matter of hours, in other parts of the body like the skin and vagina it lasts for longer," Dr Phillips says.

"There were anecdotally specific examples where if evidence hadn't been collected early, it would be very difficult to investigate the alleged assault or identify the offender."

However, she says no scientific evidence existed previously which supported the effectiveness of early evidence collection.

Explore further: Pain from sexual assault often untreated, study says

More information: Details of the research have been published in Forensic Science Medicine and Pathology. www.ncbi.nlm.nih.gov/pubmed/24752424%20%20

Related Stories

Pain from sexual assault often untreated, study says

September 14, 2012
(HealthDay)—Although most victims of sexual assault experience severe pain after their attack, fewer than one-third receive medication to ease their discomfort, according to a new study.

Repeated sexual assault victims report more psychological problems than previously thought

May 22, 2014
According to recent studies, one in five adult women and one in 100 adult men have reported being raped. The prevalence increases to two in five among women and one in five among men who report experiencing other forms of ...

BUSM professor outlines best practices for treating victims of sexual assault

August 31, 2011
Judith A. Linden, MD, associate professor of emergency medicine at Boston University School of Medicine (BUSM) and vice chair for education in the department of emergency medicine at Boston Medical Center (BMC), has written ...

Recommended for you

Best of Last Year—The top Medical Xpress articles of 2017

December 20, 2017
It was a good year for medical research as a team at the German center for Neurodegenerative Diseases, Magdeburg, found that dancing can reverse the signs of aging in the brain. Any exercise helps, the team found, but dancing ...

Pickled in 'cognac', Chopin's heart gives up its secrets

November 26, 2017
The heart of Frederic Chopin, among the world's most cherished musical virtuosos, may finally have given up the cause of his untimely death.

Sugar industry withheld evidence of sucrose's health effects nearly 50 years ago

November 21, 2017
A U.S. sugar industry trade group appears to have pulled the plug on a study that was producing animal evidence linking sucrose to disease nearly 50 years ago, researchers argue in a paper publishing on November 21 in the ...

Female researchers pay more attention to sex and gender in medicine

November 7, 2017
When women participate in a medical research paper, that research is more likely to take into account the differences between the way men and women react to diseases and treatments, according to a new study by Stanford researchers.

Drug therapy from lethal bacteria could reduce kidney transplant rejection

August 3, 2017
An experimental treatment derived from a potentially deadly microorganism may provide lifesaving help for kidney transplant patients, according to an international study led by investigators at Cedars-Sinai.

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.