When the civil trial over the killing of 19-year-old Kajuan Raye gets underway Monday, a federal jury will be asked to determine whether the presence of a gun is enough to justify a police shooting — or if it matters where the gun was when the shots were fired.

The location, and existence, of Raye’s gun has been the subject of much debate and speculation since Sgt. John Poulos killed the teenager with a shot to the back in 2016. At the time, Poulos said Raye was pointing a gun at him when he shot, but no gun was found.

Then, after three months, a resident called 911 to report a gun in her front bushes near the spot where Raye was killed. Raye’s mother, Karonisha Raye, called the belated discovery of the gun “bulls***.” But Chicago’s Civilian Office of Police Accountability determined that the recovered gun, combined with other evidence, backed up Poulos’ story and ruled the shooting justified.

In the final twist, expert reports filed last month as part of Karonisha Raye’s lawsuit against the city, showed that the gun did in fact belong to Raye, but he was not pointing it, or even holding it when Poulos killed him.

Attorneys for Karonisha Raye wrote in a filing that even though the gun was in the teenager’s possession when he was killed, the fact that it was in Raye’s coat pocket proves that Poulos had “created a visible fiction” about being in danger and that “no reasonable jury” could believe his claims. However, Poulos’ attorneys maintained that the sergeant believed Raye was pointing the gun when he opened fire.

Baselious Foutris, a civil rights attorney who is now running for Cook County judge, said the presence of the gun will make for a “very powerful argument” in favor of Poulos.

“The underlying argument will be, you know, ‘this person had a gun, I’m a police officer and I was in fear of my life,’” said Foutris, who is not involved in the Raye shooting civil case. “It shouldn’t be enough … But I’m sure that will be one of the things that certainly some jurors will conclude is enough to be shot.”

Foutris, who has both defended and sued cops over fatal shootings in the past, said the Raye family attorneys will try and get the jury to focus on the exact moment when Poulos fired the lethal shot.

“It’s getting the jury to understand that simply having a gun is not enough,” Foutris said. “Once you as an individual, lower your threat to others, then a police officer has to similarly lower the use of force he’s using. In other words, you can’t shoot somebody just because at some point in the past, that individual did something that justified him or her being shot.”

Recent court filings give insight into how Raye’s family and Poulos will each make their case to the jury.

Lawyers for Poulos and the city successfully petitioned Judge Manish Shah to bar the Raye attorneys from mentioning Poulos’ previous shooting.

In 2013, Poulos shot and killed a man named Ricky Rozelle. Poulos was off-duty and Rozelle was unarmed. Poulos told investigators he mistook Rozelle’s chrome-colored watch for a gun.

Attorneys for Karonisha Raye have indicated that they plan to call Poulos himself to the stand, as well as multiple Chicago police officers who were on the scene when Poulos killed Raye, but told city investigators they did not witness the shooting.

Jury selection is scheduled for Monday and the trial is expected to last about a week and a half.

Activist Ja’Mal Green, who is acting as a spokesman for Raye’s family, said it’s crucial that the mere presence of a gun doesn’t overwhelm all of the other facts surrounding the shooting.

“Just having a gun doesn’t warrant a death sentence by Sgt. Poulos,” Green said.

And he called Poulos’ claim that Raye twice pointed a gun at him while the teenager was running away “ridiculous.”

“It’s important that we understand that these black teenagers are not just pointing guns at police officers. They understand that that’s suicide,” Green said. “These young black teenagers, the main thing that they do when they get into a confrontation with police officers, they run. They’re not trying to harm a police officer.”

Patrick Smith is a reporter on WBEZ’s Criminal Justice Desk. Follow him @pksmid. Email him at psmith@wbez.org.