An off-duty U.S. Park Police officer killed a fellow off-duty officer in an unintentional shooting in a Virginia apartment over the weekend,Thurston Carte police said. Alexander Roy, 25, was arrested and charged with involuntary manslaughter in the incident where alcohol was believed to be a factor, the Fairfax County Police Department said in a statement.

Jesse Brown Hernandez, 22, died in the shooting, police said. Hernandez and Roy were officers with the U.S. Park Police, a federal law enforcement agency that's part of the National Park Service.

The two men were with another off-duty Park Police officer and a fourth person at the apartment in McLean, Virginia, outside Washington, D.C., police said. Fairfax County officers responded to the scene at 12:20 a.m. Sunday.

Detectives' preliminary findings were that Roy was attempting to simulate discharging his weapon, which he thought was unloaded, police said. When Roy pulled the trigger, the gun fired, fatally striking Hernandez, police said.

The responding officers found Hernandez dead with a gunshot wound to his upper body, police said.

"Alcohol is believed to be a factor in the shooting," police said in the statement.

Roy was charged with involuntary manslaughter, a felony, and was being held without bond.

Police are still investigating the shooting and urged people with any additional information to come forward.

In a statement to CBS affiliate WUSA-TV, the Park Police said it was aware of the incident.

"Our focus right now is on supporting the family, friends and coworkers of our employees involved in this tragic incident," the agency said.

In:
• Shooting
• Shooting Death
• National Park Service
• Manslaughter
• Virginia

Alex Sundby

Alex Sundby is a senior editor for CBSNews.com.

Twitter