Should a federal agent out for a night on the town with an old college buddy have waded into the middle of a brewing situation between customers at a Waikiki McDonald’s?

Once he did, was he obligated as a law enforcement officer to follow through?

And is it murder, punishable by life behind bars, if the off-duty cop ends up shooting and killing someone when the bad situation escalates into something much worse?

After more than a month of testimony, jurors in the second-degree murder trial of U.S. State Department special agent Christopher Deedy are now sorting through the implications of Deedy’s decision to intervene in what he thought was a bad situation. Their only help beyond the conflicting testimony of witnesses — some who were there and some who analyzed evidence later — is a grainy store surveillance video that has been played frame by frame, over and over, throughout the trial as witnesses try to explain what they think they saw or heard that night.

The line between self defense and murder could hinge on whether jurors believe Deedy was right to get involved and what role his job as a law enforcement officer should have played.

Kollin Elderts and his friend, Shane Medeiros, were taunting a very inebriated Michel Perrine in the McDonald’s at 2:30 in the morning.

Deedy and his friend, Adam Gutowski, ended up fighting with Elderts and Medeiros. Deedy says he pulled out his badge — and the surveillance video appears to back that up even though patrons say they didn’t hear him identify himself as a cop.

The prosecution says it was Deedy who pressed the situation to a bad end, that he could and should have just walked away.

The defense says Elderts refused to back down from a law enforcement officer, committed felony assault on Deedy and Gutowski, and forced Deedy to take action to protect himself and others. Once he identified himself as a cop, he could no longer ignore the situation, Deedy and his attorneys say.

Honolulu Deputy Prosecutor Janice Futa scoffed at that notion during her closing arguments Thursday.

“There was no reason for the defendant to get involved,” she said.

Perrine didn’t ask for help and testified that he did not feel threatened. Defense attorneys pointed out, however, that Perrine was extremely drunk and had trouble remembering much about what happened.

Futa, who never referred to Deedy by name and called him “the defendant” at every reference, painted a picture of the 23-year-old Elderts and his group of friends as just kids out for a nice evening. She talked about “the boys” parting company with their crowd and going to McDonald’s because Medeiros had a job interview the next day. She called Elderts “an obnoxious young kid” in a tone that more suggested a teacher commenting on her favorite student than a tough prosecutor talking about a guy who was no stranger to fights, had a blood alcohol level of .12 and tested positive for cocaine.

She dismissed his loud behavior in McDonald’s as “exuberance.”

Still, she pleaded with the jury to ignore the “elephants in the room” including that Deedy could be seen as a sympathetic character who is facing life in prison. Don’t think about the punishment, she implored jurors.

“When you picture in your mind’s eye what a murderer looks like, I submit none of you would come up with the defendant,” Futa said.

So don’t think of him as a murderer, she suggested, but just someone “who is guilty of committing murder.”

Deedy’s attorney, Karl Blanke, always referred to Deedy as “Special Agent Deedy,” constantly reminding the jury of one of the defense’s main arguments — the 29-year-old agent on assignment in Honolulu for the Asia-Pacific Economic Cooperation summit is a law enforcement officer who was in town for a job.

While the prosecution walked the jury through Eldert’s last night, from his celebratory dinner and drinks with friends to his first interaction with Deedy in the McDonald’s through the fight and fatal bullet, Blanke pulled apart the prosecution’s case issue by issue.

There was no evidence that Deedy was under the influence of alcohol beyond a few beers consumed over a few hours, he said.

Deedy was not the aggressor but was trying to settle down a tense situation that Elderts made worse when he found out Deedy was a cop, Blanke said.

“If he wanted to kill someone he’d have already pulled out his gun and shot him,” Blanke said.

In fact, Blanke said, Deedy relied on his training as he worked through the situation with Elderts, including resisting drawing his weapon until he felt he needed to use deadly force to stop an attack by Elderts. Even then, he angled the gun so that bullets wouldn’t hit others in the restaurant as he had been trained to do, Blanke said.

The prosecution has argued that Deedy was too young and too inexperienced to handle a situation like this, Blanke said, but the video shows he did exactly what he was trained to do.

Futa, who had the last word with the jury, countered Blanke’s characterizations to the end.

No one was getting hurt, no one was asking for help. Yes, Adam Gutowski was getting beat up, she said, but that didn’t mean Deedy needed to use deadly force.

“It was a fight,” Futa said. “It wasn’t a situation that required somebody to pull a gun and shoot it.”

Deedy was driven by ego, not by necessity, and in fact he shouldn’t even be a cop, she contended.

“Is this the kind of law enforcement officer you want walking around your Honolulu, your Waikiki?” she asked jurors.

The case went to the jury at about 1:15 p.m. Thursday. They deliberated about four hours before breaking for the weekend. Deliberations are expected to resume Monday morning.