Martha Zerehi is a close friend of the Salinas family, who owns United States Fire Protection. She says police were able to track down the suspect, 30-year-old Jade Douglas Harris, because he left his car at the scene of the crime.
"He called the police, or 911, to report his car stolen," said Zerehi. "So the police told him, 'Don't worry, your car is not stolen, come and get it. You car is good.' That's how he got arrested."
Harris is accused of killing two workers at the business and Susana Perez-Ruelas at her home two blocks away. Perez-Ruelas is also the wife of United States Fire Protection owner Tony Salinas.
Zerehi says the gunman appeared at the shop to inquire about a Camaro for sale. Perez-Ruelas and her son had arrived at the shop after the two workers, Josimar Rojas and Irene Cardenas, had been killed. Zerehi says the gunman forced Perez-Ruelas and her son to take him to the car that was parked down the street.
Zerehi says the 13-year-old told the gunman to take the keys and leave, and that's when more shots were fired.
"He pulled the gun on the boy and he says, 'You know how easy it is for me to kill you right away?' When he did that, the mother pushed him away from the boy and the gunman, furious, killed the mother in front of the boy and then shot the boy."
Zerehi says the boy suffered a gunshot to the shoulder and played dead until the gunman left. The boy was treated and released from the hospital.
Salinas' mother, Maria Fuentes, was also shot in the face. Fuentes remained in the intensive care unit as of Friday night.
Harris does have a criminal record, which includes convictions for robbery, attempted robbery and possession of a concealed weapon.
Harris is being held without bail at the Men's Central Jail and is set to be arraigned in the murder charges in Downey on Monday.