The facts of Derek Carlile's case are not in dispute; the jury will have to decide whether his actions were a tragic lapse in judgment or an act of criminal negligence.
Prosecutors say back in March, Carlile left a loaded gun in his van with his four young children. His 3-year-old son grabbed the weapon and unintentionally shot and killed his 7-year-old sister.
"No reasonable person would leave a loaded unsecured gun in a van with four children," said Lisa Paul, the prosecutor handling the case.
But Carlile's attorney calls it a tragic mistake, not a crime. The defense team hinted that Carlile may tell his side of the story on the witness stand. In the end, jurors only heard his sobs.
"Emotion comes out in these cases. It's just something you can't keep out of a trial, and how it will affect the trial -- it's hard to say," said defense David Allen.
The attorney said Carlile and his family have suffered immensely since losing their daughter.
"Derek accepts responsibility and is at fault for leaving a firearm in his car on March 10. There's no question about it; Derek screwed up. He knows that," said Allen.
The defense attorney calls it a momentary lapse in judgment, but the prosecutor says Carlile is guilty of criminal negligence.
The prosecutor says Carlile knew his son was fascinated by guns, and as a police officer, understands firearm safety better than most. She believes Carlile's grief is heartfelt, but asked jurors not to be swayed by the officer's tears.
"And it's your duty now to not let sympathy for the defendant play into your deliberation," Paul said.
The issue for jurors is whether they can isolate those facts from the raw emotions they saw displayed over the course of the trial.
"This is obviously an emotional case. And people are human, and I'm sure it's going to be difficult for the jury," said Chief Criminal Deputy Prosecutor Joan Cavagnaro.
The jury will resume deliberations on Tuesday.
A guilty verdict could put Carlile behind bars for more than two years, but the judge has the discretion to impose a lighter sentence.