Thomas Jacob Sanford, who also lit church on fire, was killed by police who responded to September shooting

The former US marine who opened fire in a Michigan church and set it ablaze in September was motivated by “anti-religious beliefs” against the Church of Jesus Christ of Latter-day Saints, the FBI said on Friday.

While friends of the gunman in the deadly shooting have said he harbored hatred for what is widely known as the Mormon church, the FBI had previously declined to specify the motivation behind the attack that left four people dead and the church burned to the ground, except to say it was a “targeted” act of violence.

The gunman, Thomas Jacob Sanford, 40, was killed by law enforcement responding to the shooting.

“I am confirming this is a targeted act of violence believed to be motivated by the assailant’s anti-religious beliefs against the Mormon religious community,” Jennifer Runyan, special agent in charge of the FBI’s Detroit field office, said in a prerecorded video message. The agency declined to share further information on what led to its conclusion.