DNA results that led to Grant conviction 'scientifically corrupt,' says professor

An expert in forensic genetics raised serious concerns about the Thunder Bay lab and DNA test results which linked accused killer Mark Grant to Candace Derksen’s 1984 murder.

Tells retrial judge he believes lab scientists disregarded information that didn't fit their narrative

Mark Edward Grant was convicted in 2011 of second-degree murder in connection with the 1984 death of Candace Derksen, 13. In 2013, the Manitoba Court of Appeal ordered a new trial, ruling the trial judge was wrong to exclude evidence that the defence argued suggests Derksen might have been killed by someone else. (CBC)

An expert in forensic genetics raised serious concerns about the Thunder Bay lab and DNA test results which linked accused killer Mark Grant to Candace Derksen's 1984 murder in testimony Monday. 

 "I'm very concerned about the quality of work that came out of that laboratory," Bruce Budowle said, adding some of the test results were "unexplainable," "scientifically corrupt" and driven by "suspect bias."

Grant was charged with second-degree murder in 2007 in the death of the 13-year-old. Candace's body was found frozen and bound with twine in an Elmwood storage shed in 1985, seven weeks after she went missing. 

Budowle, a genetics professor at the University of Northern Texas and former FBI employee, was called as an expert by Grant's defence team to review reports from Molecular World. Police sent several key pieces of evidence to the lab, including the twine, for retesting in 2006.

Police also sent DNA from a new list of persons of interest, including hair and blood samples from Mark Grant, to see if he or others matched the DNA on items seized at the crime scene. The lab was chosen because it offered two kinds of DNA tests not previously available to police.

Scientists conducted three rounds of tests. It was DNA on the twine that the lab linked to Grant.  

However, Budowle said the scientists "incorrectly interpreted" their own findings and ignored data and inconsistencies in the DNA tests that would have excluded Grant.

Budowle explained there was a DNA marker on the twine which could not have come from Candace or Grant, but the information was disregarded.

He believes, he told the court, that instead of analyzing all of the results and then comparing them to Grant's DNA profile, they looked at Grant's sample first and found patterns with the results then disregarded data which didn't align with their hypothesis.

"The fundamentals of DNA typing were violated in this analysis," he said.

In Budowle's opinion the test results were "at best inconclusive." He also questioned whether the same samples of DNA were used in all three tests.

Grant's defence team also raised questions about the possibility the DNA samples could have become contaminated by lab staff or police investigators who didn't wear full protective gear.

Budowle said "significant" contamination was possible.

Crown attorneys Michael Himmelman and Brent Davidson will begin cross-examining him on Tuesday.

The judge-only retrial is being presided over by Justice Karen Simonsen.