By Friday evening, investigators were still working to piece together the confusing string of incidents that unfolded about noon along Pico Boulevard and on the campus of Santa Monica College.
Authorities had not yet released the name of the gunman or the victims and declined to discuss what may have spurred the rampage. For hours the campus remained on lockdown as police methodically searched buildings for additional victims and possible other suspects. At a press conference held after nightfall, a Santa Monica police official said investigators believed the gunman had acted alone. The official also corrected an earlier police report that six victims were killed and said that a "person of interest" taken into custody had been cleared of any involvement.
The first signs of trouble came about 11:50 a.m., when gunshots rang out at Kansas and Yorkshire avenues, a quiet neighborhood nestled along the Santa Monica Freeway.
Jerry Cunningham-Rathner had watched her son walk out the front door of her home a few minutes earlier and rushed outside, fearing he had been shot.
Instead, looking across the street, she saw a house engulfed in flames. A man standing in front of the house was dressed all in black, with an ammunition belt around his waist and a large rifle in his hands.
"He looked like a SWAT officer," she recalled later.
Firefighters would later find the bodies of two men inside the house. Police sources, who requested anonymity because of the ongoing investigation, said the men were Samir Zawahri, 55, the owner of the house, and one of his adult sons. A second son is suspected of being the shooter, the sources said.
Cunningham-Rathner looked on in horror as two cars approached. The man pointed his weapon at the first, a Mazda hatchback, and yelled at the driver to stop. Cunningham-Rathner said he motioned for the woman driving the second car to keep moving. When she hesitated, the man opened fire on her silver Infiniti, wounding the driver slightly.
Laura Sisk, 41, the driver in the first car, froze, she later said. She knew President Obama was in town for an event a few miles away and thought momentarily the man might be a Secret Service agent. She quickly realized that wasn't the case.
"You're going to drive me to Santa Monica College and let me out," she recalled the gunman saying.
She begged him to take the car instead. "No. You're driving," he responded.
Before sitting next to Sisk, he fired several shots aimlessly around the neighborhood with what authorities later said was an "AR-15 style" semiautomatic rifle, according to witnesses.
Other than telling her where to turn, the man said little during the mile drive down Pico Boulevard toward the college campus, Sisk said. He was calm, she said.
Sisk said she was crying and shaking as she drove. The gunman reassured her. "He told me to calm down," she said. "He said he'd let me go if I didn't do anything stupid."
Near Cloverfield and Pico boulevards, the gunman fired at the outside of a public bus from front to back, shattering the windows. Passengers threw themselves to the floor for cover, said Marta Fagerstroem, a student from Sweden, who was on the bus and studying for an exam.
A woman sitting in the back row was grazed in the head by a bullet, witnesses said.
"It happened so fast," said Fagerstroem, her voice quavering. "You don't expect this."
After shooting at the bus, Sisk recalled the gunman shouting at her to "'Go! Go! Go!' So I drove, drove, drove."
They continued toward the campus. At a school parking lot at 20th and Pearl streets, the shooter opened fire on two people in a Ford Explorer, police said. The driver died at the scene, and the passenger was badly wounded. Shortly after, Sisk said, the man ordered her to let him out. After he exited, she sped down the block and then got out of her car and ran.