Authorities in Missouri say a cop is dead and another is facing criminal charges after what they believe began as an ill-advised game involving live ammunition.

According to KTVI, 24-year-old Katlyn Alix was at a St. Louis-area residence with 29-year-old officer Nathaniel Hendren and his partner early Thursday morning when the shots were fired.

According to investigators, Hendren and his partner were on duty at the time of the incident. Alix was reportedly off duty and the three gathered at Hendren’s home.

As court documents allege, Hendren retrieved a revolver at one point and loaded it with just one bullet. The one-year veteran of the St. Louis Metropolitan Police Department allegedly pointed the weapon at an area away from the home’s occupants and pulled the trigger, which did not result in a discharge of the firearm.

Alix then took the gun and pointed it at Hendren, investigators believe, and it again did not go off. When Hendren took it back, he allegedly pointed it at Alix.

Hendren’s partner, who police believe told the pair that they should knock it off, was reportedly walking out of the room when the fatal shot rang out.

Police say Hendren and his partner rushed Alix to an area hospital where she was pronounced dead.

The deceased officer was identified as a veteran of the U.S. Army who had been with the agency for about two years. According to CNN, she is survived by a husband.

Her mother, Aimee Chadwick, said Alix loved being a cop and went beyond the call of duty even when she wasn’t on the job.

“There will never be another Katie,” her mom said. “She was the most generous person, kindest person. If you needed her, she would be there.”

Police arrested Hendren, though as of the latest reports available it was unclear whether he was still in custody. He is expected to face criminal charges including first-degree involuntary manslaughter and armed criminal action.

A prosecutor involved in the case described it as “devastating” and “heart-wrenching” to learn of the incident involving police officers.

“Today, as much as it saddens me and my staff to file these charges, Katlyn and her family deserve accountability and justice,” Kimberly Gardner said.

[Featured image: Katlyn Alix, handout]