Closing arguments set in murder trial

Closing arguments begin Tuesday in the trial of Mark Edward Grant, accused of murdering Winnipeg schoolgirl Candace Derksen.

The defenceclosed its case Monday, after calling just one witness in the trial, which started Jan. 17.

John Waye, a genetics professor at McMaster University in Ontario, testified Friday that "bad science" was behind some of the DNA analysis linking Grant to material found at the scene.

Waye, called by Grant's defence team, has worked with the RCMP and testified in several high-profile criminal cases involving DNA, including that of B.C. serial killer Robert Pickton.

He told the jury he wasn't critical of all the lab work done by Molecular World in Thunder Bay, Ont., just the parts that fit Grant and those that don't.

Grant, now 47,was arrested in 2007 after DNA found at the crime scene was linked to him through advanced testing techniques.

Candace, 13,was allegedly grabbed off the street Nov. 30, 1984, bound with rope and left to freeze to death inside a brickyard shed. Her body was found in the shed on Jan. 17, 1985, following an exhaustive search that included hundreds of volunteers.

Three pubic hairs were found on or near her body, although police have said she wasn't sexually assaulted.

Four scalp hairs that appeared to have been lightly bleached near the roots were on Candace's clothing. Police weren't able to test the hairs for DNA until technology improved in 1993.

By that time, police were looking at a dangerous sex offender as a potential suspect in what proved to be a false lead. The Derksen case would gather dust for several more years.

In 2006, police learned the Thunder Bay lab had the ability to run more extensive hair-shaft DNA tests. The testing involved identifying the maternal lineage of the subject donor, which is DNA passed from mother to child.

DNA tests are at the core of the case against Grant because it is the only physical evidence the Crown has against Grant, whosaid nothing to implicate himself when questioned by police, insisting the entire time on his innocence.

Once closing arguments are completed, Court of Queen's Bench Associate Chief Justice Glenn Joyal, who is presiding over the case, will instruct the jury and send the 12 men and women off to deliberate.