[Onkel Neal]

Neither the victims nor the gunman have been named by authorities as of Monday morning, although officials said the gunman had been arrested multiple times in different municipalities.

"The shooter is relatively transient but has roots to this area," Matthew Desarno, special agent in charge of the FBI Dallas office told reporters Sunday night. He added that the shooter was not on any sort of watch list.

Paxton said it was his understanding that the gunman was a "more of a loner." He had been to the church several times before and was welcomed in, the attorney general said.