A DNA expert has linked Johnny Altinger's blood to Mark Twitchell, the Edmonton man accused of killing and dismembering him.

RCMP forensic specialist Robert Schimpf testified Thursday at Twitchell's first-degree murder trial that Atlinger's blood was found on a number of items seized from Twitchell's car, home and his parents' house, including a hunting knife and a pair of jeans.

The jeans had Altinger's blood on the knee and back pocket, and Twitchell's DNA was found on the waistband. Schimpf said the probability that anyone but Twitchell wore those jeans was one in 4.4 trillion.

Altinger's blood was also found on items seized from Twitchell's rented garage, including knives in a hunter's processing kit and a metal pipe, the jury was told.

Twitchell, 31, is accused of killing Altinger, 38, on Oct. 10, 2008. The Crown alleges Twitchell, an aspiring filmmaker, lured Altinger to a rented garage in south Edmonton by posing as a woman on an online dating site.

Schimpf told the jury Altinger's blood was found on the shoe and belt Twitchell was wearing when he was arrested three weeks later.

Earlier Thursday, the jury was told by Alberta's assistant chief medical examiner, Dr. Bernard Bannach, that graphic descriptions of dismemberment found in a document on Twitchell's laptop are medically credible.

si-bannach220

Medical examiner Dr. Bernard Bannach testified Thursday that graphic descriptions of dismemberment found in a document on Mark Twitchell's laptop are medically credible. (CBC)

Crown prosecutors read Bannach portions of SKconfessions, a document they allege is a true account of how Twitchell killed Atlinger.

Bannach said the descriptions match his own experiences dealing with bodies in autopsies.

Some of Altinger's bones were found in a storm sewer in a north Edmonton alley on June 4, 2010.

Bannach testified only the torso was recovered, which was about half the skeleton. Bannach could see clear evidence of dismemberment with a saw and a sharp knife.

The jury was also told a human tooth was found at the bottom of the sewer. Schimpf testified the tooth belonged to Altinger.

With files from the CBC's Janice Johnston