Jack Wilson, 71, poses for a photo at a firing range outside his home in Granbury, Texas. Picture: AP Photo/Jake Bleiberg

A man wearing a wig and fake beard raised suspicion when he walked into a church service in Texas before opening fire with a shotgun and killing two people, a volunteer security guard who shot the assailant said on Monday.

The victims of Sunday’s shooting, identified as Anton Wallace, 64, of Fort Worth and Richard White, 67, of River Oaks, were also members of the civilian security force at West Freeway Church of Christ, the state’s attorney general said.

Jack Wilson, the head of the security detail, fired a single shot that took down the gunman, who has been identified by authorities as Keith Thomas Kinnunen, 43, of River Oaks.

Wallace was serving communion at the church in the Fort Worth suburb of White Settlement and was approached twice by the suspect in the moments before the gunfire rang out.

“When he sat back down the second time, shortly after that, he stood up, turned, and produced a shotgun,” Wilson told NBC News.