Defence in retrial for suspect in Winnipeg teen’s death questions DNA evidence

WINNIPEG — Testimony at day five at the re-trial of Mark Edward Grant in the 1985 death of Candace Derksen focused on how DNA samples were tested and handled in 2000 and 2001.

The details were so technical that at some points even the trial judge needed the Crown and defence to move more slowly when explaining terms.

Court started with cross-examination of Crown witness Tod Christianson, who analysed DNA found on evidence at the scene where the 13-year-old girl was found frozen, hog-tied inside a shed in an industrial yard.

Christianson analysed DNA testing of evidence found at the scene, including three pieces of gum, twine and the girl’s clothing.

Christianson explained there was a threshold below which DNA results would be excluded for further testing.

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The defence continued a line of questioning to build a theory that DNA could potentially become compromised if handled too much, which Christianson said was possible.

He admitted he didn’t wear a mask when analysing the twine. On Thursday, the trial was told he had handled the twine with his bare hands before DNA testing.

However, Christianson testified that touching the twine with bare hands didn’t exponentially increase the risk of contamination.

It was DNA found on the twine that led to the arrest of Grant in 2007. In 2011, he was convicted of second-degree murder but two years later his conviction was overturned because the jury wasn’t made aware of evidence that could have pointed to an unknown suspect.

This re-trial in a charge of second-degree murder is being heard before a judge alone.

(CTV Winnipeg)

The Canadian Press