The shooting happened around 11 a.m. at 7550 Bellfort Avenue, near Leonora Street, in southeast Houston.
Police said there was a verbal dispute between two men inside Martinez Tire Shop when the argument turned physical.
A third man, who had possibly been changing his own tire outside of the shop, attempted to intervene during the dispute and shots were fired, police said. As the third man turned away from the gunfire, the suspect fired more shots at him. Both of the victims died at the scene.
The suspect then left the scene westbound on Bellfort in a mid-2000s dark-colored GMC truck, according to police.
Authorities said it's unclear why the suspect was at the tire shop.
Police said they have surveillance video of the incident as well as several witnesses to help with their investigation.
No other injuries were reported in the shooting.
“We’re still trying to determine if he was an employee or a customer. But he engaged some type of dispute ... verbal dispute with another male that was inside the tire shop,” an investigator said. “Unfortunately the two males -- the one inside the tire shop and outside the tire shop -- both died on the scene.”
Levert Jenkins was driving by moments after the shooting. He said he sprung into action and performed CPR to try to save the victim's life.
"I just washed the blood off of my hands. It’s just ... I can’t believe it. It doesn’t even feel real,” he said. “My condolences go out to the family. My heart goes out to the family.”
The brother of one of the victims said it's time for the senseless violence to end.
"Why do y'all continuously shoot people?" he said. "Stop killing people who've got families to go home to. Stop ... killing people who've got kids 'cause who ... is going to raise his kids now?"