SUTHERLAND SPRINGS, Texas (AP) — The gunman responsible for the deadliest mass shooting in Texas history died from a self-inflicted gunshot wound and also had drugs in his system, according to an autopsy report released Thursday.

Devin Patrick Kelley, 26, opened fire during church services on the First Baptist Church in Sutherland Springs last November, killing more than two dozen people. He was later found dead in a vehicle after he was shot and chased by two men who heard the gunfire at the church.

devin Autopsy: Texas Church Shooter Had Drugs In System, Died By Suicide

Devin Patrick Kelley (credit: CBS News)

The autopsy released by the Travis County Medical Examiner’s Office said Kelley’s cause of death is suicide from a single gunshot wound to the head. The autopsy, first reported on by San Antonio TV station KENS, also says toxicology tests detected marijuana and anti-anxiety drugs in his system.

Investigators have said the attack appeared to stem from a domestic dispute Kelley was having with his mother-in-law, a member of the church who wasn’t present that day. Kelley had been discharged from the Air Force for assaulting his wife and child, and served 12 months’ confinement following a 2012 court-martial.

One family that lost several relatives during the mass shooting has sued the federal government, saying that even though Kelley was criminally convicted the military failed to enter the information into a database used to conduct background checks of gun buyers. The error, according to the lawsuit, allowed Kelley to buy the assault-style rifle he used in the attack.

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