A Texas man is accused of fatally shooting his brother’s suspected killer, gunning him down in a Houston parking lot, officials say.

Houston police found 38-year-old Luis Martinez shot to death outside La Michoacana, a supermarket on the city’s northwest side, on May 13, according to a criminal complaint. Spent shell casings littered the ground around Martinez’ white Dodge Ram, and a ShotSpotter system detected a total of 22 gunshots.

Surveillance cameras at the scene captured the shooting, documents said. They also show the gunman, later identified as 33-year-old Angel Chavira, arrive in the parking lot with his wife and three children, police said.

Video shows Chavira pull into the parking lot and park near Martinez’s pickup, documents said. Martinez walks into the supermarket, then Chavira and his family get out of their car and enter the store together.

With his family by him, Chavira follows Martinez around the store, staring at him, documents said. Martinez never notices.

Chavira and his family exit and get back into their car. Moments later, another vehicle arrives in the lot, picks up his wife and kids, then leaves, documents said.

Chavira is alone now, waiting for Martinez, police said.

Chavira’s brother had been killed in a prior shooting that was still under investigation, according to the documents. He told a detective at the time that he thought Martinez was the one responsible.

Martinez knew Chavira might be after him, a friend told investigators. Days before his death, Martinez confided that he was in danger, that Chavira had threatened to kill him, according to the friend.

Unaware that Chavira had been shadowing him in the store, Martinez leaves and walks to his truck. The moment he climbs into the driver seat, Chavira drives up beside him and opens fire, police said.

After the first volley, Chavira pulls out of the parking space, maneuvers to another angle and fires several more shots, the video shows. Then he gets out of his car and fires off more rounds while standing outside the truck, police said.

Martinez died as a result of “multiple gunshot wounds to his head and body,” according to investigators.

Chavira was arrested on a charge of murder, according to the Houston Police Department.

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