LA CROSSE, Wis. -- The jury is now deliberating the fate of the West Salem man charged with killing his parents.

A verdict could come at any time in the Eric Koula murder trial. The jury started deliberating about 4 p.m. Monday.

Depending on which way the jury goes, Eric Koula could soon be sleeping in his own bed or back in his jail cell.

But before they got the case, it was the last chance for the defense and prosecution to sway the jury to their side as they delivered their closing arguments.

One question has dominated the court room since the beginning of this month:

"Who is Eric Koula?" asked prosecutor and La Crosse County District Attorney Tim Gruenke.

If you ask the prosecution, they said he's a liar and a murderer.

"He's a man of many secrets, as I told you in the opening. In May of 2010, he was in desperate financial straits. He was facing a huge mountain of debt, no realistic way of paying it off in his lifetime -- unless he got money from somewhere else. 'Desperate' might be an understatement for the situation that he was in," said Gruenke.

But if you ask the defense, Koula was a loving son, scared and struggling to come to terms with the loss of his parents.

"Eric would not and did not commit these crimes because of the love that existed between the father and a son, and a son and a mother," said defense attorney Jim Koby.

But the defense's biggest argument is that investigators found zero forensic evidence tying Eric Koula to the crime scene.

"We now know that there are no fingerprints. We know that there is no DNA. We know that there is no murder weapon. We know that there are no witnesses," said Koby.

"There is no DNA evidence that directly links him to the crime on this date. But there is physical evidence. A check was taken from the residence on May 21 and cashed on May 22. The fact that he lies about it and lies about cashing it shows you how important it is to link him to the murders on that date," said Gruenke.

The $50,000 check Koula signed in his father's name isn't the only piece of evidence the prosecution said Koula lied about. There's also the note reading, "Fixed you" Koula now admits to planting in his own mailbox.

"It's the final piece of the puzzle. It's the final piece that shows you beyond any doubt that he's lying, that he's manipulating, that he's diverting attention. And the only reason to do that is because he's guilty," said Gruenke.

"I think what the note proves is that Eric was scared. And I think what the note proves is that Eric was stupid,” said Koby.

The defense has been trying to convince the jury a professional killer gunned down Dennis and Merna Koula, not their son. They said the single lethal shots in the victims' heads indicate the work of an experienced killer.

But the prosecution said that was just the most efficient way to kill them.

"If you want it done quick, you're going to aim for the head. Anybody would do that -- amateur, professional, organized, unorganized. That's how you would do it if you're going to do this," said Gruenke.

But did Eric Koula do this?

Or are there enough holes for the jury to find reasonable doubt?

If the jury does not reach a verdict by 9 p.m. Monday night, they will be sequestered in a hotel, then resume their deliberations Tuesday morning.