Kirsty Wynn is a senior reporter at the Herald on Sunday.

Cold-case killer convicted with science help from NZ

Daniel Morcombe.
Daniel Morcombe.

A New Zealand forensic scientist helped provide the crucial breakthrough in a horrific Australian murder cold case.

DNA evidence provided by Catherine McGovern from Environmental Science and Research helped convict serial sex offender Brett Peter Cowan, 44, this week for the murder 10 years ago of Queensland schoolboy Daniel Morcombe.

Brett Peter Cowan.
Brett Peter Cowan.

McGovern's team matched DNA from the murdered 13-year-old's toothbrush to a fragment of bone found during the search for his remains.

Cowan abducted Daniel from a Sunshine Coast bus stop.

Police long suspected the sex offender but it took a confession during a four-month undercover operation to get an arrest. Cowan believed he was about to be part of a successful crime gang and confessed to the murder, believing his associates would clean the crime scene. His associates were all undercover police officers.

Police used information Cowan provided to locate 17 bone fragments, Daniel's Globe skate shoes, and a pair of Bonds underpants.

Cowan's defence argued he made up the confession to be part of the crime gang and suggested the bone fragment wasn't Daniel's.

But McGovern told the court via video link from Auckland her testing found the bone sample was 540 times more likely to have come from Daniel than any other person in Queensland.

McGovern explained Daniel's toothbrush established a full DNA profile. That was then compared to a humerus or arm bone search crews found.

Other items were sent to New Zealand for testing, including the shoes found at the site.

ESR spokesman Stephen Corbett said New Zealand scientists were called about six times each year to help with Australian cases.

"There are a couple of DNA technologies we have that they don't. Our experience is world class and we are taking it to the world at the moment."

Corbett said the case was terribly tragic but the scientists involved remained impartial dealing only with the facts of science.

"In a case like this there is some satisfaction in an outcome being reached."

On Thursday, after Cowan was found guilty, Queensland Assistant Police Commissioner Michael Condon thanked the New Zealand scientists for their part in securing the guilty verdicts.

- Herald on Sunday

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