A St. Louis police officer accused of accidentally killing a female colleague while playing a variation of Russian roulette pleaded guilty Friday and was sentenced to seven years in prison. Nathaniel Hendren, 30, had been scheduled to go to trial March 23 on charges of first-degree involuntary manslaughter and armed criminal action.

The seven-year sentence was the maximum for involuntary manslaughter.

Nathaniel Hendren is accused of fatally shooting Officer Katlyn Alix during a Russian roulette-style game. St. Louis Police

He was accused of fatally shooting 24-year-old Katlyn Alix, also a St. Louis police officer, at his home in January 2019 while he was supposed to be on duty elsewhere. Hendren's male partner, also on duty, was at the home, too. Alix, a married military veteran, was off-duty at the time.

Get Breaking News Delivered to Your Inbox

"The reckless behavior that took place that early morning has left an unfillable void for her grieving husband, her parents, and a host of loving family and friends," Circuit Attorney Kim Gardner said in a statement.

Hendren's lawyer, Talmage Newton IV, has called Alix's death a "tragic accident," but a lawsuit filed by Alix's family claimed Hendren forced other girlfriends to play similar games.

A probable cause statement from police, provided by Gardner's office, offered a chilling account of the game that led to Alix's death.

"The defendant emptied the cylinder of the revolver and then put one cartridge back into the cylinder," the statement said. Hendren allegedly spun the cylinder, pointed the gun away and pulled the trigger.

The gun did not fire. The statement said Alix took the gun, pointed it at Hendren and pulled the trigger. Again, it didn't fire.

Hendren "took the gun back and pointed it at the victim (and) pulled the trigger causing the gun to discharge," the statement said. "The victim was struck in the chest."

The other male officer told investigators he warned Hendren and Alix not to play with guns and reminded them they were police officers. He was about to leave when he heard the fatal shot, the statement said.

The male officers drove Alix to a hospital where she died.

Hendren was "in love" with Alix, court documents say

CBS affiliate KMOV reports that court documents stated that while at the hospital, Hendren "spontaneously stated to his supervisor… that he did not try and kill the victim because he was in love with her and they were in an intimate relationship and were planning on moving into his apartment."

The court documents also state that Hendren, Alix and the only other officer who was present at the time of the shooting were "very close friends who had a close work and social relationship," KMOV reported.

Alix was a patrol officer who graduated from the St. Louis Police Academy in January 2017.

Hendren left the police department soon after the shooting and his state peace officer license was suspended.