The suspect, 47-year-old Juan Marquez of Hawthorne, was taken into custody Saturday and booked into the Orange County Jail on a charge of murder in the killing of 42-year-old Sandra Fernandez, according to the Tustin Police Department. Marquez is a former boyfriend of Fernandez, according to police.
The video featured in the media player above is from a previous report and will be updated.
Marquez is being held without bail.
Officers initially responded to multiple calls about gunshots near 17 and Yorba streets just after 6 p.m. Thursday.
When they arrived, they found Fernandez, of Anaheim, shot dead behind a small white SUV.
Witnesses reported seeing a man dressed in black fleeing the area and driving away in a dark-colored older model sedan.
Marquez allegedly waited near her workplace before the shooting, the investigation revealed.
After the killing, Marquez fled the country through the San Ysidro Port of Entry, police said.
Detectives later identified him as the suspect and obtained an arrest warrant.
U.S. Customs and Border Protection agents detained Marquez Saturday afternoon as he attempted to re-enter the United States. Tustin police detectives then took him into custody.
Police said the shooting appeared to be an isolated incident and that there is no ongoing threat to the public.