FERGUSON, Mo. – A security guard fatally shot a gunman at a Ferguson gas station overnight after an argument led to an exchange of gunfire. The security guard now faces criminal charges.

The St. Louis County Prosecuting Attorney’s Office has issued charges of voluntary manslaughter and armed criminal action against Maury Adams, according to an update Saturday from the Fergsuon Police Department.

Adams was arrested and is being held in the St. Louis County Justice Center on a $50,000 cash-only bond.

The shooting happened around 1:30 a.m. at a Ferguson QuikTrip in the 10000 block of West Florissant Avenue. Investigators have not yet disclosed the identity of the suspect involved.

The Ferguson Police Department says the incident unfolded shortly after the suspect tried to make a purchase, and there was “an apparent disagreement over required identification for the transaction.”

The suspect left, then quickly returned to the store. Shortly after that, an altercation heated up between him and an on-duty security officer.

According to surveillance footage reviewed by police, the situation escalated to the point that both the suspect and the security officer pulled out firearms. An exchange of gunfire followed.

The suspect was fatally shot at the scene. The security guard, identified as Adams, was also shot, but while wearing a bulletproof vest. He suffered non-life-threatening injuries and was released from the hospital Saturday morning after treatment.

The St. Louis County Crime Scene Unit and Ferguson Police Department are investigating the shooting. If you have any relevant information to add to the investigation, contact the Ferguson Police Department at 314-522-3100.