Only one in 52.9 trillion Caucasians could have left the DNA found on a T-shirt found at the feet of Amy Rolfe the day she died, a forensic DNA analyst said in state District Court Monday.

That person is Joshua David Giddings, who is on trial for allegedly murdering Rolfe on July 22, 2005, the analyst said.

Stephen Gresko, who formerly worked with Myriad Genetics Inc., also said he found Rolfe's DNA on two swatches taken from the inside of the Ecko brand shirt.

Earlier testimony included Giddings' friend, who said he loaned him the shirt the week of the homicide and an acquaintance of Giddings who said she remembered seeing him wearing the T-shirt on July 22.

Rolfe and Giddings were named by Gresko as possible contributors to a mixture of DNA found on a white sock and two men's tennis shoes, which were both located in a bag found when Giddings was apprehended the day of the beating death.

Blood stains on those items were consistent with Rolfe's DNA profile, Gresko added.

Giddings' lawyers questioned the accuracy of the testing and Gresko's projections.

Gresko tested samples with the DNA profiles of Rolfe, Giddings, Rolfe's boyfriend Michael Mix, Rolfe's ex-husband Chris Rolfe and the man the defense says killed the 26-year-old library worker, Richard Alan King Jr.

Although the defense asked if King's DNA might have been found in a semen sample taken from Rolfe's body because King has similar aspects to his DNA as the specimen, Gresko said the probability of Mix leaving the sperm was one in 220 quadrillion.

Lewis and Clark County Attorney Leo Gallagher asked Gresko if he found any evidence consistent with King's profile.

"I couldn't include him in any of the evidence, no," Gresko responded.

Red and brown stains from throughout Rolfe's Helena home tested positive for traces of Rolfe's blood, including swabs taken from the kitchen refrigerator upstairs and the basement, where her body was found in a pile of blankets and other assorted laundry.

Jurors arrived for their third week of service visibly worn. The seven women and five men will get a day off today.

The trial will resume tomorrow, when more of the prosecution's witnesses from out of state will be available.

District Judge Thomas Honzel said he hopes to hand it over to the jury by Friday.

Another witness called by the prosecution was Giddings' grandmother Colleen Acord.

Acord said she spoke with her grandson several times after his arrest. She said she continuously told him to cooperate with law enforcement.

If convicted of the charge of deliberate homicide, Giddings faces a possible sentence of life in prison.

The 32-year-old is up on additional charges of tampering with evidence, possession of dangerous drugs and tampering with a witness or informant in connection to the murder.

She said her grandson consistently said he did not kill Rolfe, but was "sort of involved."

In a later conversation with his grandmother, as read to the court by Gallagher, Giddings denied telling Acord he played a part in the murder or covering it up.

Giddings at first told law enforcement that it was Rolfe's boyfriend who killed the mother of three, but later said King was responsible.

As she smiled at her grandson from the stand, Acord said she and Giddings have a good relationship.

"He's always been forthright with me," she said.