Joshua Slaven, 31, son of Cedar Hill Mayor Rob Franke, was fatally shot after he allegedly broke into the home of Gareth Long Tuesday night, the Dallas Morning News reported.
Investigators said Long was questioned in the case, but not arrested.
Long told his lawyer that he and his wife were sleeping when they heard someone enter their home through a bedroom window.
Long said he retrieved his handgun and confronted the intruder in a hallway, repeatedly stating that he had a weapon and telling him to leave. The intruder did not leave, so Long shot at him, he told his lawyer.
"It's very unfortunate that Mr. Long was forced into a position of having to defend himself, his wife and his home from a nighttime intruder," said Chris Knox, Long's attorney. "Nobody ever asks to be placed in such a life-threatening position, but Mr. Long's actions were absolutely justified and completely protected under Texas law."
Cedar Hill city spokesman Corky Brown said evidence found during the investigation supports Long's account of the incident.
Mayor Franke lives on the same street as Long, several blocks away.
Court records show that Slaven has recently been involved in an altercation at Franke's home, in which he pleaded guilty to misdemeanor assault charges and an emergency protective order was issued against Slaven.
Investigators have not said whether the break-in and the incident at Franke's home are connected.