Monday, July 13, 2020

Cat Hair Helps to Convict Man of Murder

Must read

In a National First, HFSC Begins Blind Testing in DNA, Latent Prints

The Houston Forensic Science Center has expanded its blind quality control program to its Forensic Biology and Latent Print sections. This unique program allows...

New DNA technique means pointing the finger at the right identical twin just got easier

DNA profiling (or genetic fingerprinting) has proved a revolutionary tool for forensic investigators as a means to identify potential suspects, exonerate the innocent and...

Fingerprint Fabrication/Forgery – The Bourne Supremacy

Saw this good example of what a Fingerprint Fabrication/Forgery looks like from 'The Bourne Supremacy' if you were unsure what one looked like. So "Spoiler Alert" for...

How a forensics breakthrough nailed George Green, the chimney sweep killer

THE brutal murders of an elderly church-going woman and her young niece shocked Melbourne in mid-November 1938. Burglar George Green had also raped the 17-year-old...
Michael Whyte
Crime Scene Officer and Fingerprint Expert with over 7 years experience in Crime Scene Investigation and Latent Print Analysis. The opinions or assertions contained on this site are the private views of the author and are not to be construed as those of any professional organisation or policing body.
- Forensic Podcast -

For the first time ever, mitochondrial DNA from shed cat hair was accepted as evidence in a U.S. legal proceeding and helped to convict a suspect of murder.

The case, which will be outlined in the November issue of the Journal Forensic Science International: Genetics, could set a precedent, such that pet hair may be more commonly introduced as evidence in U.S. trials.

“Dog hair has been used in both state and federal courts,” co-author Beth Wictum told Discovery News. “Cases range from animal theft to animal cruelty, murder, sexual assault, bestiality, and pretty much anything you can think of.”

Wictum, who is associate director of the Veterinary Genetics Laboratory Forensics Unit at the University of California at Davis, and her colleagues analyzed the single light orange-colored cat hair that was found in one of the victim’s jean pockets. The individual, from Clay County, Missouri, was found severely beaten with his throat violently lacerated to near decapitation.

Both the victim and the primary suspect lived with cats, so the cat hair by itself did not mean much, given how frequently felines shed. As any cat owner knows, strands of cat fur seem to wind up everywhere. Prior studies have demonstrated how shed cat hair can cling to everything from curtains to clothing.

The researchers therefore obtained and sequenced mitochondrial DNA (mtDNA) from the single hair. This is a type of DNA that passes down from mothers to their offspring. Another type of DNA, nuclear, provides more information because it encodes for the majority of the individual’s genome.

“Shed hair usually doesn’t have nuclear DNA because it is in the hair follicle, so we test the mtDNA in the hair shaft,” Wictum explained. “However, because cats and dogs groom themselves, we sometimes get nuclear DNA profiles from shed pet hair.”

For this case, only the mtDNA was available, but the researchers were able to compare and contrast it with mtDNA from a large general database as well as from samples of fur obtained from both the victim’s and the suspect’s cats. That was quite a challenge, since the suspect lived with 11 cats, and 8 of those were reported to be related.

The murder trial of the State of Missouri versus Henry L. Polk, Jr. represents the first legal proceeding where cat mitochondrial DNA analysis was introduced into evidence. The mitochondrial DNA evidence was initially considered inadmissible due to concerns about the cat dataset and the scientific acceptance of the marker. Those concerns were subsequently addressed, and the evidence was deemed admissible.

Source: Discovery News

- Advertisement -

More articles

- Advertisement -

Latest article

Using the NCIC Bayesian Network to improve your AFIS searches

This National Crime Information Centre (NCIC) Bayesian network is based on the statistical data of general patterns of fingerprints on the hands...

DNA decontamination of fingerprint brushes

Using fingerprint brushes across multiple crime scenes yields a high risk of DNA cross-contamination. Thankfully an Australian study has discovered a quick and easy way to safely decontaminate fingerprint brushes to prevent this contamination risk and allows the brushes to be safely reused even after multiple cleaning cycles.

Detection of latent fingerprint hidden beneath adhesive tape by optical coherence tomography

Adhesive tape is a common item which can be encountered in criminal cases involving rape, murder, kidnapping and explosives. It is often the case...

Presenting Fingerprint Comparisons in Court using Forensic Comparison Software

This video gives the fingerprint technician some ideas on how to present a Fingerprint Comparison result to the court that looks professional. To accomplish this...

New modified fingerprint chemical that fluoresces touch DNA on clothing

In sexual assault and burglary investigations, the recovery of DNA from items that have been handled by the suspect is very important....