Tyre marks found underneath the bridge where Daniel Morcombe disappeared didn't match the tread patterns on the four-wheel drive belonging to the Queensland schoolboy's accused killer, a court has heard.
Tread patterns left under that Sunshine Coast bridge and those on Brett Peter Cowan's Mitsubishi Pajero are entirely different in photographs, scientific officer Sergeant Nicole Tysoe says.
"So I formed the opinion that the white Pajero did not make those tyre impressions located underneath the bridge," she told a Queensland Supreme Court jury on Monday.
Photographs of Cowan's tyres were taken after he voluntarily gave his car to police to examine on Christmas Eve in 2003, less than three weeks after 13-year-old Daniel was last seen at the Kiel Mountain Road overpass in Woombye.
Sgt Tysoe examined the 4WD, which she described as in "moderate condition" but dirty with various items left inside, including a pram, rope, rubbish, fishing gear, tools, raincoats and paperwork belonging to Cowan.
During her examination, Sgt Tysoe took test strips to check for human and animal blood and used A4 tape lifts to pick up any hairs or fibres inside the car.
There was no evidence indicating there was blood inside the car, she said, and the A4 tape lifts were sent to Queensland Health for testing.
It wasn't until 2011 that the tape lifts were first examined by hair experts. They failed to find any hairs that may have belonged to Daniel, Sgt Tysoe said.
While testing of Cowan's 4WD failed to turn up forensic evidence, Sgt Tysoe said she wouldn't have expected to find any DNA if an uninjured person was sitting voluntarily in the front seat.
"It doesn't mean that somebody wasn't in the car," Sgt Tysoe said.
"Considering what (DNA testing) was available to us back in 2003 then it's not unreasonable to expect that we found nothing at the time."
The trial in Brisbane continues.
