GRANBURY, Texas — Despite training members of his church's security team to be vigilant, Jack Wilson never expected he would have to shoot down a man as he did during Sunday's service at the West Freeway Church of Christ.

Wilson was hailed as a hero by local law enforcement officials after stopping a gunman who killed two members of the congregation in the town of White Settlement, deacon Anton “Tony” Wallace and fellow security team member Richard White. Wilson, who owns a gun range, told NBC News on Monday that he was still grappling with the death of his two friends and concerns for the close-knit congregation.

"I don’t feel like I killed a human, I killed an evil and that’s how I’m coping with the situation," Wilson said.

Wilson, a former reserve deputy for the Hood County Sheriff's Office, said he felt an instinct the moment the stranger walked in with his long coat, wig and a fake beard.

Wilson said he walked back to the church's audio and visual room to make sure there was a camera on the man, later identified as Keith Thomas Kinnunen, while White kept an eye on him from his chair in the auditorium.

Kinnunen got up from his place on the pew twice before approaching Wallace during communion and pulling out a shotgun.

"Richard did get his gun out of the holster, he was I think able to get a shot off but it ended up going into the wall," Wilson said. "The shooter had turned and shot him and then shot Tony."

Wilson, 71, said that he had his gun out as the shooter turned to the front of the auditorium, but had to wait a second to get a clear shot as members of the church reacted to the attack. The man went down and didn't get up from the head wound as other congregation members on the security team came in.

He said the congregation began training a security team about 18 months ago, after nearly two dozen churchgoers were killed in Sutherland Springs in late 2017.

And so Wilson began training members as he does many others who come to his gun range, On Target Firearms Academy. He said that had the team not been in place, the outcome for the more than 200 members of the church could have been much worse.

"The whole time from when he stood and turned till it was over was less than six seconds," Wilson said of the shooter. "I was watching the replays with the FBI yesterday, it’s between four and six seconds from the start to finish."

Blayne Alexander reported from Granbury and Doha Madani from New York.