Skip to content

Saanich police's finder of lost fingerprints

Saanich forensics expert invents new technique for lifting prints hidden under handwriting
Forensic Identification
Saanich police forensic officer Shane Coughlan invented a new technique which allows police officers to

Saanich police Const. Shane Coughlan is a problem-solver.

As a longtime member of the department’s forensic identification section, he is challenged – day in and day out – with assisting in crime solving through processing of physical evidence.

But sometimes his job is hampered by the limitations of known forensic techniques.

“Several years ago we had a string of bank robberies where the hold-up note was being left behind,” Coughlan says. “My boss as the time had developed several fingerprints (off the notes), but one of them was obscured by the writing. The writing went across the middle of the fingerprint.”

The chemical ninhydrin, which police departments use to locate fingerprints on paper, reacts with the skin’s oils left behind and turns the prints purple. But that colour is difficult to distinguish from pen ink.

“So I started thinking about the problem and I played around with it, and I developed a technique where I used a different chemical to fade the pen ink, but not effect the fingerprint. So you could actually see the extra detail in the fingerprint that was hidden by the writing,” Coughlan says.

The police officer spent the next couple years sharing his technique with colleagues, who eventually convinced him to formalize it by conducting scientific experiments and publishing his findings.

Coughlan was published in the Journal of Forensic Identification in August 2012 after perfecting the technique.

“Initially all I did was play around a bit and it worked. But a full, proper experiment had to be with the same items, same methods, and repeatable to get the same results,” he says.

“When I developed the technique there was absolutely no intention of writing articles and being published, it was because I wanted to find a way to make something happen. And I did.”

In late October Coughlan was awarded the August Vollmer Innovation in Forensic Technology award from the International Association of Chiefs of Police.

“We are extremely proud of Shane and are pleased that he has been recognized for his efforts. Our personnel from the Forensic Identification Section provide exemplary service to our investigative units every day. We are fortunate to have a very talented group of individuals,” says Chief Const. Mike Chadwick.

“The commitment and ingenuity displayed by Const. Coughlan in the development of this process is outstanding. This development will allow our officers, as well as officers around the world, a greater opportunity to make an identification of suspect fingerprints.”

Retired Victoria Police Department Det. Const. Bob Elder also received an August Vollmer award, for Significant Investigative Value in a Major Crime.

Elder, who spent six years with VicPD’s computer forensics unit, was skilled in recovering and extracting data from broken electronics, such as damaged circuit boards, cell phones and destroyed hard drives.

Coughlan, who’s been a Saanich police officer for 14 years, says he and his colleagues have successfully used his fingerprint technique to solve crimes and get charges approved.

He says the beauty of what he developed is that the technique is quick to do and the chemicals used are already readily available in police forensics labs.

“I’m just happy that some place in Australia can do this and now solve a robbery or a hold-up because of it,” Coughlan says.

kslavin@saanichnews.com