The gun that discharged inside the pocket of a substitute teacher in an Alabama first-grade classroom did so after it came in contact with a knife in his same pocket.

“I’m so sorry it happened, and I hope those kids have no memory of it after time passes,’’ the 74-year-old teacher, Henry Rex Weaver, told AL.com on Thursday.

The incident happened midday Friday, March 22, at Blountsville Elementary School. Authorities at the time said only that the gun discharged in Weaver’s pocket and that a fragment injured one student.

Through court records made public Thursday and the interview with Weaver, a clearer picture emerged.

According to an affidavit in the misdemeanor criminal cases against Weaver – reckless endangerment, third-degree aggravated assault and possession of a firearm on school grounds – this is what happened inside the elementary school classroom: Weaver had a Taurus .380 pistol and a knife in his front right pocket. He bent over to pick up an item off the floor and when he straightened back up, the knife, a clip-on, entered the trigger guard of the pistol and caused it to discharge into the floor.

A fragment struck a 7-year-old girl in the leg. There was a welt on the girl’s leg, records state, but the fragment did not penetrate the skin.

Weaver was taken into custody at the scene, interviewed and then booked into the Blount County Jail. He was released the same day on $3,000 bond and has a court date set for May.

Weaver said he had put his pistol up for several days because his permit had expired. He renewed his permit on Thursday and left for school Friday morning with the intention of storing the gun under the armrest of his locked vehicle.

He took a quick phone call as he was about to go into the school – he had to be there at 7:20 a.m. – and was running slightly behind schedule when he got out of the car. “I completely forgot about the pistol being in my pocket,’’ Weaver said.

Weaver is obviously upset over the incident and said he knows he will never again be back inside a classroom. “Oh, I could never substitute again,’’ Weaver said. “The parents are upset, and I understand that.”

He said he plans to stand before his fellow church members Sunday and explain what happened. “Time is a healer,’’ he said, “and hopefully that will happen here.”