16 Jun 2015

NZ case helps forensic expert win award

5:03 pm on 16 June 2015

A Tasmania Police forensics expert whose evidence helped convict a man of murder in New Zealand has received an award for the paper he wrote about his work.

Sergeant Gerard Dutton

Sergeant Gerard Dutton spent four days in court giving evidence in a New Zealand murder case. Photo: AAP

Sergeant Gerard Dutton is in charge of the ballistics section at Forensic Science Services Tasmania.

He was asked to conduct an independent review of the ballistics evidence in the New Zealand murder case by the detective in charge of the investigation.

His evidence in court lasted for four days, in which he was questioned about unusual marks on the bullet caused by separate actions during the loading and firing process.

Sergeant Dutton was able to prove the bullet came from the defendant's gun.

"Ultimately the case hinged solely upon being able to relate the bullet to the sawn-off rifle used and for [more than] four days in the New Zealand High Court I explained the significance of this evidence," he said.

Aaron James Harvey was convicted of the murder of Carl MacDonald in 2008 and sentenced to four years in prison.

Sergeant Dutton said it was an unusually difficult case.

"The ballistics evidence in this murder case was extremely technical and complex," he said.

"There were many tests to be done, and when I'd complete one set of tests and look at the results, then I'd have to think about that, then look at something different.

"It just took a long time to methodically work through what I had in front of me, and it took two weeks, which was extraordinary."

Sergeant Dutton's paper about his work on the case, 'A case study of the interpretation of extraordinary toolmarks on a fatal bullet', was published in the Journal of the Association of Firearms and Toolmark Examiners.

It has won the Harry Delaforce Award from the Australia New Zealand Policing Advisory Agency's National Institute of Forensic Science.

Sergeant Dutton said he wrote the paper because the case was so technically interesting.

"I just thought anyone who does this work, and who enjoys doing it, will learn from this particular case and from what I was able to learn from it, so when faced with these sort of opportunities it's almost, you know it's a responsibility to write about it for the benefit of your peers."

Sergeant Dutton was recently elected as the ballistics representatives on the Australian Field Forensic Science Accreditation Board.

-ABC