HOUSTON (AP) — A Texas man has been charged with murder in the fatal shooting at a crash scene of a suspected drunken driver who authorities say plowed into his sons as they helped push their family's broken-down pickup truck along a dark, narrow, rural road.

David Barajas, 31, and his sons, 12-year-old David Jr. and 11-year-old Caleb, were about 50 yards from their Houston-area home when a car crashed into them. David Jr. died at the scene, while Caleb died later at a hospital.

Neighbors said they heard gunshots minutes after the Dec. 7 crash near Alvin, about 30 miles southeast of Houston. Jose Banda, the 20-year-old driver who hit the boys, was later found shot in the head. His death was ruled a homicide.

Brazoria County sheriff's investigator Dominick Sanders said Monday that witnesses told authorities they saw Barajas, right after the crash, walk to his home and then return a few minutes later and approach Banda's vehicle. Evidence showed one shot was fired, he said.

"Every time we would pursue a lead, it always came back to Mr. Barajas," Sanders said. "We have numerous statements placing him there at the car in close proximity to the victim at the time the gunshot was fired."

Barajas was indicted for murder Friday and turned himself in Sunday. He was being held Monday in the Brazoria County Jail on a $450,000 bond. Court records did not list an attorney for him.

Gabriel Barajas, David Barajas' brother, had previously said his sibling had remembered the crash as a "blur" and called speculation that his brother or another family member might have been responsible for Banda's murder "ugly."

Barajas' wife, Cindy, was in the truck when it was hit, along with the couple's 8-year-old daughter and 3-month-old son.

A search of Barajas' home found ammunition that is consistent with the bullet that killed Banda, but authorities have not located the weapon used in the shooting, Sanders said. The case is "going to be much more difficult if we don't have a weapon," he added.

Gunshot residue tests were done on both Barajas and Banda, and authorities are still waiting for those results, Sanders said.

Investigators also are awaiting DNA test results of some "biological material" that was found at the scene. Sanders declined to elaborate on the material that is being tested.