LA CROSSE, Wis. -- The jury in a double homicide trial watched a three-hour recording of the defendant's interrogation Tuesday morning.

It was day seven in the trial of a West Salem man charged with killing his parents over money two years ago at their home in Barre Mills.

John Christopherson, the lead investigator from the Department of Criminal Investigation, had interviewed Eric Koula numerous times before this recording.

But this July 2010 interview was a turning point in the investigation. Christopherson said this was when it stopped being an interview and became an interrogation.

"You're in a situation where there's been some tough times and there's not a lot of money there. And sometimes it creates a situation where we need to act," Christopherson said to Koula. "No, I did not, no," said Koula.

In this recording, the jury saw the moment where Christopherson told Koula his alibi of being at a Shopko around the time his parents were thought to have been murdered didn't hold up. He's not in the surveillance video.

"We don't see your truck, don't see you outside looking at plants. We even pulled the videos from inside the store just in case maybe you made a mistake and went inside," Christopherson said to Koula.

"I didn't go inside the store," said Koula. "Okay, and reviewed, and reviewed, and reviewed," said Christopherson.

During cross-examination, the investigator explained part of his interrogation strategy.

"I talk about parents being there for you and, in some instances, parents aren't there for you. And as a result, we react and do things we might regret later," said Christopherson in court Tuesday. Koula maintained his innocence, repeatedly saying he didn't do it.

"Look John, I didn't hurt them. I really, I didn't do anything," said Koula."
"I know you wouldn't hurt them," said Christopherson.
"I did not," said Koula.
"And that's why you wanted to make sure that they went quickly," said Christopherson.
"I did not do this," said Koula.
"And in order to let the pressure come out, sometimes you have to release it," said Christopherson.

Koula was arrested shortly after that interrogation wrapped up.

The defense pointed out Tuesday that investigators never found any blood or gunshot residue on any of Koula's clothing or in his truck.

He has pleaded not guilty. He faces life in prison if convicted.

The trial is expected to continue into late June.