A Maine State Police scientist testified Wednesday that DNA evidence found on the rear door of a Saco house where a masked gunman broke in and shot two people almost certainly matched Gregory Owens’ profile.

The DNA analyst, Jennifer Sabean of the Maine State Police Crime Lab in Augusta, testified at Owens’ trial that there is only a 1 in 123 quadrillion possibility that the genetic material collected from the garage door window of 25 Hillview Ave. could belonged to anyone other than Owens.

Owens, 59, who is on trial in U.S. District Court in Portland, has denied accusations that he drove from his home in Londonderry, New Hampshire, to the home of Steve and Carol Chabot on Dec. 18, 2014, to shoot his wife, Rachel Owens, who was visiting there.

Sabean’s testimony during the second week of Owens’ trial was the first time jurors heard evidence from a witness that directly linked Owens to being at the scene of the shooting. Owens and Steven Chabot were each shot three times in separate rooms but survived.

Assistant U.S. Attorney Darcie McElwee rested the case for the government after Sabean’s testimony. Owens’ attorney, Sarah Churchill, began the defense’s case in the afternoon and expects to call more witnesses Thursday.

Depending on whether Owens chooses to testify, McElwee and Churchill said closing arguments could be Friday or Tuesday, since Monday is a federal holiday.

Churchill challenged Sabean’s testimony during cross-examination, questioning whether enough genetic material existed for Sabean to make her determination.

The DNA evidence could prove crucial to the case, since none of the victims could identify the gunman.

Rachel Owens, who survived the shooting but still has a bullet lodged in her head, testified last week during the trial that the man who shot her wore a black mask.

Steve Chabot, who was also shot through his bedroom door after coming face to face with the masked gunman, told jurors last week that he could only discern that the person who shot him wore glasses beneath the mask, was about 5 feet 9 inches tall and had an athletic physique.

Police witnesses said the gunman got into the house by breaking the window of a back door into the garage of the Chabots’ home and then breaking another window to open the door from the garage into the kitchen.

When police in Hudson, New Hampshire, pulled over Owens in his vehicle several hours after Steve Chabot called 911 to report the at 2:47 a.m. shooting, they testified that they saw Owens’ hand was cut and that he had wet boots in the back of the vehicle.

Another witness from the state crime lab, scientist Kimberly James, testified Wednesday morning that the tread of the boots seized from Owens matched a footprint left in a flower bed outside the Chabots’ home.

James said she could not say with certainty that the footprint left outside the Chabots’ home came from Owens’ boot.

Prosecutors had focused many questions to earlier witnesses on blood evidence collected in the shooting investigation, including one blood drop left in the doorway of the bedroom where Rachel Owens was shot. But Sabean testified Wednesday that she could not say with certainty whose blood it is and that DNA testing showed a mixture of genetic material belonging to both Rachel Owens and Steve Chabot.

Investigators say Owens shot his wife as his double life made up of lies began to crumble. His mistress from Wisconsin, Betsy Wandtke, testified Monday that she had discovered Owens had not left his wife years before, as he had told her, and had come to doubt his claims about being a military operative who went on frequent covert missions overseas.

Owens has pleaded not guilty to two federal counts: interstate domestic violence, punishable by up to 20 years in prison, and using a firearm during and in relation to a crime of violence, punishable by up to life in prison. After the federal trial, he will face state criminal charges, including aggravated attempted murder.

Much of the government’s case before presenting the DNA evidence focused on trying to undermine Owens’ alibi that he gave to police, that he was in New Hampshire and knew nothing of the shooting.

The police began building their timeline against him starting with Steve Chabot’s 911 call at 2:47 a.m, on Dec. 18. Police worked backward to shortly after midnight when Owens was shown on a surveillance camera footage at the Hudson, New Hampshire gas station, and then again around 4:30 a.m. when Owens was seen in serveillance footage of a Dunkin’ Donuts in Londonderry, New Hampshire.

Police witnesses said they reviewed camera footage of bridges between Maine and New Hampshire in the hours around the shooting, but none of the footage showed Owens’ vehicle.

In a recorded interrogation shown to jurors, Owens told police after the shooting that he was home at the time, working on his computer for much of the night on a business proposal, and had sent an email around 2:30 a.m.

Saco police Detective Fredrick Williams testified on Tuesday that he conducted an analysis of Owens’ computer that showed Owens had accessed his computer at no time between 9:49 p.m. on Dec. 17 and 5:16 a.m. on Dec. 18. Williams said the activity on Dec. 18 shows that Owens himself set back the clock on his computer by three hours before sending an email to his work colleagues.