SANTA MONICA, California (CNN) -- The gunman's rampage began at a home in this beachfront city, leaving two dead inside. Then he carjacked a woman and fired at a public bus. It all ended when police shot him dead at Santa Monica College as students studied for finals, a mile from the house.
His blood trail, however, left four people dead Friday in Santa Monica, which abuts Los Angeles and is renowned for its liberal openness.
A law enforcement source with knowledge of the investigation told CNN on Saturday that the gunman had suffered mental health issues. A couple of years ago, he was hospitalized for treatment after allegedly talking about harming someone, according to the official.
It's not clear whether the state government or his family committed him for treatment or whether he committed himself. It's also unclear under what circumstances he was released. The gunman has yet to be identified.
Authorities have found no link to domestic or international terror, the official added.
Also Saturday, one of four victims shot dead was identified as Carlos Navarro Franco, 68, who resided in one of Los Angeles' west neighborhoods near Santa Monica, authorities said. He was the driver of an SUV who was gunned down on the campus, police said.
The three other victims have not yet been identified. The two-year college remained closed Saturday as police combed the crime scene for clues to the rampage, which began shortly before noon at an acquaintance's house in one of Santa Monica's breezy neighborhoods.
Dressed in black and toting an assault-style rifle, the man's apparently random gunfire became the nation's latest disturbing killing spree, ending with his death in the college library and leaving this tourist beachfront city reeling with shock.
A neighbor's account
Jerry Cunningham stepped onto her porch when she heard the shots. She saw the gunman firing at a neighboring house, which was also on fire.
The neighborhood, regarded as working class, sits beside Interstate 10 -- "the last affordable area in Santa Monica," with houses under $1 million, said nearby resident Carmen Franco, 47, who's not related to the killed victim. "Nobody can afford to buy now here in Santa Monica," where houses are easily seven figures, she added. The area's only trailer park is on the other side of the highway.
Investigators believe the gunman knew the dead people in the house, but police were unsure of the connection.
Cunningham then observed the gunman force at gunpoint a woman to stop her car.
Another car approached. The gunman waved it by, Cunningham said. That driver, also a woman, hesitated for just a moment, and the gunman "fired three shots directly into her and the car," Cunningham said.
The motorist was wounded in the shoulder, she said. That driver was hospitalized and is in stable condition, authorities said.
The gunman then got into the first car and forced the woman to drive off with him, police said.
During their ride, 911 calls poured in, keeping police on the gunman's path, said Sgt. Richard Lewis, a spokesman for the Santa Monica police.
As the car headed toward the campus of the community college, where 30,000 students are registered, he opened fire on a passing bus, slightly wounding three people, Lewis said.
He was carrying an "AR-15 style rifle," pistols and "more clips for the rifle," Lewis said.
Police have described the shooter as a 25- to 30-year-old man who was dressed in black and wearing a tactical vest.
As the car pulled onto the campus, the man fired into Franco's red SUV, killing him and critically wounding his passenger, police said. Franco's vehicle crashed after the shooting, Lewis said.
The gunman then abandoned the hijacked vehicle -- leaving the driver unhurt -- and fled on foot, shooting at police, Lewis said.
College employee Joe Orcutt saw the firefight between the man and officers and took off running, but ran the wrong way and found himself facing the gunman.
"He looked over at me, and I looked at him," Orcutt said. "He just panned his gun and trained it on me, and I just jumped behind the building and he shot at me."
The gunman was "very calm, not running around." He was just "looking around for targets very casually," he said.
"He just looked like he was standing there posing for the cover of an ammo magazine or something. It was bizarre."
Inside a classroom
Jasmine Franco, 22, was in a classroom at Santa Monica College -- next to the library -- waiting for her English class to start at noon on Thursday. Little did she know that the gunman began his rampage at a house near to where she and her mother, Carmen, live.
Jasmine Franco's friend had left the room to fill his water bottle and she was sitting alone when she first became aware something was wrong. "You could hear rumbling, a lot of rumbling, it sounded like an earthquake or something," she said, referring to the sounds of gunfire mixed with the footfalls of people running.
But her 11 classmates and the teacher appeared oblivious, and continued their banter until her friend burst back in. "His whole face was red and his veins were coming out of his neck, he was trying to calm himself," Franco said.
"I'm entirely serious," she said he told them. "There's a shooter on campus."
He told the class he had heard a gun unload. "He said it just sprayed and unloaded tons of rounds."
Not knowing what to do, "We just sat there."
The teacher left the classroom to see what he could learn and, moments later, ran back inside. "He says, 'They just unloaded a magazine.' He said there was a lot of bullets."
At that moment, the door to the hallway locked shut -- automatically -- with a click, she said. Outside the classroom, she could see dozens of people fleeing on the cement. "We could see people running with their backpacks," Franco said. "No screaming, just running. We could just hear feet and running."
Inside the library
As the killer ran, he fatally shot a woman, then burst into the campus library, said Santa Monica Police Chief Jacqueline Seabrooks.
Another woman -- who asked not to be identified -- said she was in the building when she heard a gunshot. She took off.
In a hallway, she saw a dark-haired man in black combat boots who she initially thought was a police officer, but quickly realized was the shooter. The man was walking quietly and casually.
She and a colleague ran; gunshots rang out.
Priscilla Morales said that, when she and her friends looked out a library window and saw people running, they grabbed their belongings and prepared to leave, too, but didn't get far. "As we open the door, we hear three gunshots," she said.
So they closed the door and hid.
"I was so scared and thought literally I was going to die," she said.
"Drop it!" she heard police say, then heard gunshots and a man's screams.
The officers had shot the gunman, Lewis said.
Police said that, with the exception of his first two victims in the off-campus house, all of the other victims appear to have been chosen at random.
"My heart goes out to the families of the victims of these tragic shootings in Santa Monica, and I am praying for the recovery of those who were injured," said U.S. Sen. Barbara Boxer, D-California.
At the time of the shootings, President Barack Obama was in Santa Monica for a fundraiser a 10-minute drive from the campus, CNN affiliate KCAL/KCBS reported. His schedule was not affected.
Back in the classroom
Franco's classroom ended up waiting three hours before police arrived.
During that time, some students followed events on Twitter, but the reports of people being shot and a house burned down seemed unconnected and far-fetched. "Everything's hearsay," Franco said. "People tell you one thing, but you have no clue what's happening. You just don't know anything. The best thing to do is not worry about it. Sit down."
People kept opening the classroom door, which infuriated Franco. "You're not supposed to open the door," she said. "I'm just like, 'No, we're not going to do that.'"
Though they could see police from classroom windows, "no one came to check on us" for more than two hours, she said.
Tan-uniformed officers with big guns finally arrived and escorted students out with their hands on their heads for security -- "like inmates," Franco said. Officers shouted "Go! Go! Go!"
But at least the class was safe.
Franco called her mother, who also drove home some classmates whose cars were inaccessible behind yellow police tape.
"I went home and fell asleep," Franco said.