Traces of male DNA were found on the neck and fingernail of a 13-year-old girl found dead in a Burnaby park six years ago, but there wasn’t enough material on those exhibits to create a profile that could be matched with her accused killer, according to a DNA expert who testified in court Thursday.
Christine Crossman, a scientist with RCMP Forensic Laboratory Services in Surrey, was back in the witness stand at the trial of Ibrahim Ali in B.C. Supreme Court in Vancouver.
Ali is accused of first-degree murder in the death of the girl, whose body was found in Central Park on July 19, 2017, less than two hours after her family reported her missing at about 11 p.m. on July 18, 2017.
Ali has pleaded not guilty.
The victim cannot be identified because of a publication ban.
Crown prosecutor Colleen Smith took Crossman through all the police exhibits submitted to the RCMP lab in relation to the case.
On Wednesday, Crossman had told the jury DNA extracted from three exhibits – swabs taken from the girl’s vagina and anus – matched Ali’s DNA extracted from a discarded cigarette butt and from another sample obtained from Ali through a police warrant.
Crossman said no other comparable male DNA was found on any of the other exhibits that came to the lab.
But that doesn’t mean no other male DNA was found.
Crossman said traces of male DNA were found on one swab taken of the girl’s neck and one fingernail clipping from her right hand, but not enough material was found to create a DNA profile to compare to Ali’s DNA.
“There is simply not sufficient genetic information in the trace component to make a meaningful comparison,” Crossman said.
“You could neither determine whether it matched the sample from I.A., nor could you exclude I.A. as the contributor?” Smith asked.
(In most lab files, Ali was identified only as the “suspect I.A.”)
“Correct,” Crossman said.
When asked whether she had any doubt about the reliability of the RCMP lab’s findings in the case, Crossman said, “No, I do not.”
Defence lawyer Kevin McCullough began his cross-examination of Crossman at the end of the day Thursday.
He began by questioning her about why DNA wasn't extracted from all of the exhibits collected by police.
The cross-examination is expected to continue Friday.
The Crown's theory is that Ali and the girl were strangers to one another and that he attacked her on a trail in Central Park, dragged her into the forest and strangled her to death while sexually assaulting her.
Ali's lawyers have not outlined their theory of the case.