2016-04-07 1 in 3 trillion chance DNA was someone other than Vader: forensics expert | Global
Published by Bretton McCann,
1 in 3 trillion chance DNA was someone other than Vader: forensics expert
WATCH ABOVE: Travis Vader’s DNA was found inside the McCanns’ SUV, according to an RCMP scientist who testified at Vader’s double murder trial. Kendra Slugoski reports.
EDMONTON – A DNA expert who testified at the Travis Vader double murder trial told court the chances of the DNA found in the McCann vehicle belonged to someone other than Vader is 1 in 3 trillion.
Vashni Skipper, who works in the RCMP forensics lab, told court several items from inside the McCann SUV were swabbed and tested for DNA.
DNA found on a Boxer beer can and blood on the centre console arm rest matched the profile designated as "male 2," later identified as Travis Vader. The likelihood it was someone else’s DNA is 1 in 3 trillion, Skipper said.
READ MORE: Travis Vader late again, delays Day 19 of double murder trial
DNA found on the steering wheel came back as a 1 in 7.4 billion chance that it was someone other than Vader.
A swab from the front passenger seat turned up more DNA. The likelihood it belonged to someone else was 1 in 12 million.
The reliability of DNA evidence depends on several factors including the quantity and quality of the sample. Partial DNA profiles were obtained from the steering wheel and front passenger seat.
READ MORE: Text messages show Travis Vader used McCanns’ cellphone: Crown
During cross examination, Vader’s lawyer questioned Skipper whether science could determine if a person was inside a vehicle.
Skipper admitted the forensics cannot determine where a person was located or when DNA material was deposited.
READ MORE: Witness saw Travis Vader in SUV similar to missing McCann’s vehicle
Defence lawyer Brian Beresh painted a scenario of someone sneezing or coughing from outside a vehicle through a passenger window and leaving their DNA. Skipper told the court it would be unlikely but it couldn’t be ruled out. She testified it may be difficult to get a sufficient quantity to extract enough DNA to make a comparison, but not impossible.
Blood spatter found on cans of food that were located in the SUV confirmed a match to Marie McCann. The likelihood the blood came from someone else is 1 in 4.6 trillion.
The Defense had its own DNA analyst in court to listen to the testimony.