GREAT FALLS — Great Falls Police Department Police have charged a Great Falls man with negligent homicide in the February shooting death of Malmstrom Air Force Base airman Tristan Carlson, 21. Carlson was a 2016 graduate of Sidney High School.

According to charging documents, the Great Falls Police Department received a call at 2:27 a.m. Feb. 2 from a woman reporting there had been a pop and a person had been shot in Christopher Contardo’s bedroom in an apartment complex on the 2300 block of 14th Ave. S.

The victim was identified as Tristan Carlson, and the caller reported he was bleeding from the head and she believed he was dead.

During the 911 call, the dispatcher reported the woman could be heard speaking with a male, later identified as Contardo. Detectives believe that the woman was collaborating with Contardo about what information to provide dispatch before answering their questions.

After some silence and muffled speaking, the affidavit stated Contardo told the caller to “Tell them we were playing with the gun and it went off, and it shot him in the head.”

When GFPD and medical staff arrived just after 2:30 a.m., charging documents state it was apparent that there had been a large house party at the residence earlier in the night, and police could see numerous beer cans and other alcoholic beverages throughout the apartment.

Carlson was deceased when law enforcement arrived at the scene.

Officers located the 911 caller, who had blood on her hands from administering CPR to Carlson, and Contardo was identified as the shooter, the affidavit stated.

Police located a 9mm handgun in the bedroom. Both the chamber and the magazine were empty.

Both witnesses were transported to GFPD for interviews.

Contardo appeared shaken, according to police, and he refused to speak with detectives and requested an attorney.

The 911 caller told investigators there had been a house party that night, claiming about 12 people had been present. This number is significantly less than what officers at the scene estimated based on indicators at the scene.

The woman said she was in the living room at the time of the shooting and heard a noise she immediately knew was a gunshot before seeing Contardo exit the bedroom and telling her to call 911.

Contardo then ordered everyone to leave the residence, and the woman looked in the bedroom and saw Carlson lying facedown on the bed and bleeding from the head. She said she blocked the door and did not let anyone else in the room.

Although preliminary information indicated Contardo and Carlson were the only two people in the room at the time of the shooting, the 911 caller later told detectives that another woman had been in the room.

During an interview with that witness, she told police she, Contardo and Carlson were lying on the bed. She said she was intoxicated and drifting off to sleep but noted that Contardo sat on the edge of the bed and then paced around the room several times.

The woman said the next thing she remembered was her ears ringing, seeing that Carlson had been shot in the head and hearing Contardo yelling.

Detectives determined the gun belonged to Contardo and that he habitually kept it next to his bed.

A partial box of ammunition was found in the room, and the same type of ammo was later found in a dumpster outside the residence. The number of rounds matched what would have been in the handgun if one round had been fired.

Based on the medical examiner’s report, it was deemed “extremely unlikely” that Carlson had shot himself.

Based on statements from Contardo at the scene and witness statements, Contardo was determined to be the shooter.

He was arrested Monday on a $50,000 warrant for negligent homicide.

According to the Cascade County Detention Center, he has since bonded out.