At the scene of the crime, police noticed a Nissan pickup truck that fit the exact description of the suspect vehicle.
"The suspect actually approached them and started engaging them in conversation," says Antioch Police Lt. Leonard Orman.
Police say that suspect -- 51-year-old Lucio Rivera Avila -- went out of his way to return to the crime scene.
"He didn't necessarily have to take that route from his home in Brentwood to his work location," says Orman.
Around 1:30 a.m., witnesses say a man was arguing with a woman in the parking lot of the Del Valle Market in Antioch. They say the woman got out of the truck, then the driver ran over and killed her.
"The vehicle continues and the victim is under the vehicle and drug for a considerable distance from the parking lot out into the street," says Orman.
Down at the station, police say Avila fessed up, but he told them it was an accident. The whole thing however was captured on surveillance video camera.
"You could see on the video clearly how he backs up and he ran her over," says gas station owner Cesar Fernandez.
Police are not releasing the video, but Fernandez says it was brutal.
"They were parked right here," says Fernandez. "And he reversed back and just like slammed into her, ran her over, like from the front of the car and just started dragging her. And she was caught under the car and he just like dragged her to the street about 80 feet, probably around there, and then he backed up on the body."
Police say Avila works as a maintenance man at an apartment building in Antioch. The victim is described only as a woman in her 40s. Police say they had no strong leads on a suspect until Avila walked right into their hands.