Updated at the bottom with the suspected shooter's identity. Headline has changed. First posted at 11:59 a.m.

A man went on a shooting rampage in Orange County today, resulting in four dead and at least two wounded, authorities said.

It's not immediately clear what motivated the attacks, which started with a 4:45 a.m. fatal shooting of a woman in a home on Red Leaf Lane in Ladera Ranch and progressed with a man opening fire on motorists on streets in Santa Ana and Tustin.

In one case the suspect appeared to murder a man at the side of the road, execution-style, police said. Here's a rundown of what we know:

-Following the 4:45 a.m. residential shooting there was a 5:30 a.m. report of a carjacking at Red Hill Avenue and Nisson Road, with a victim shot and wounded but expected to survive, cops said.

-Not long after that, at Village Way near the Costa Mesa (55) Freeway in Santa Ana, a carjacking victim was murdered. Santa Ana police Cpl. Anthony Bertagna:

View OC Shooting Rampage in a larger map

Reports are that he got out of the vehicle, confronted our victim who was in his BMW, … he orders him out of the vehicle, walks him to the side of the curb and executes our victim.

-In between attacks authorities say the suspect opened fire as he drove on the freeway. Three people, one with injuries, have told people their vehicles were hit by gunfire, cops said.

-In that BMW from the last carjacking, the suspect drove to Micro Center at Edinger Avenue in Tustin and carjacked another vehicle, police said:

Two people were shot, one fatally. Cops said the suspect had “long guns” or rifles.

-When cops tried to stop the suspect, described as a man in his 20s, at east Katella Avenue and north Wanda Road in Orange, he fatally shot himself, police said.

Our sister paper OC Weekly has background on a home on Red Leaf Lane in Ladera Ranch where the first shooting is believed to have occurred. Some of the residents are no strangers to authorities, apparently.

Check back with OC Weekly for the latest.

[Added at 12:06 p.m.]: KCAL News says the suspect was 19 and that the first victim was a young woman.

The station says the gunman actually phoned police and let them know where he was before his last moments.

[Update at 2:011 p.m.]: Associated press says authorities have identified the deceased suspect as “20-year-old part-time student Ali Syed.”

[Corrected at 3:18 p.m.]: OC Weekly's identification of one of the possible victims known by a former intern at the paper was, thank god, not the case. We deleted the reference.

[With reporting from City News Service / @dennisjromero / djromero@laweekly.com / @LAWeeklyNews]

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