Updated 10:00 p.m. ET
LOS ANGELES Los Angeles police have arrested a man on suspicion of intentionally at the Venice Beach boardwalk, killing a woman and injuring 11 others.
Police say 38-year-old Nathan Campbell has been booked for investigation of murder and remains jailed Sunday on $1 million bail.
He turned himself in about two hours after the attack that occurred at around 6 p.m. Saturday. Investigators don't yet have a motive.
Witnesses reported a horrendous scene of people scattered and bloody in the popular tourist area. (Video of scenes from the incident and its aftermath can be seen at left. WARNING: Some content may be upsetting to viewers.)
A coroner's investigator tells City News Service that the dead woman is 32-year-old Alice Gruppioni of Italy. CBS News correspondent Carter Evans reported she was on her honeymoon.
Police say another victim was critically hurt, two were in serious condition and others were treated for less serious injuries.
Witnesses told police and reporters the driver seemed to be in control of the vehicle, deliberately trying to hit people, reports KCBS in Los Angeles.
One witness told KCBS: "."
Louisa Hodge, 35, who was out enjoying the day on the Venice Beach boardwalk with a friend visiting from San Diego, said the scene was bloody and gruesome.
"It was blocks and blocks of people just strewn across the sidewalk," Hodge said.
The driver fled the scene and hours later, just as police were circulating word that they were seeking a black Dodge with a driver in his 20s, he walked into a police station in neighboring Santa Monica and turned himself in.
The site isn't far from the Santa Monica Farmer's Market where a 2003 crash left 10 dead and 63 hurt, after an 87-year-old man's car accidentally roared through the market.
According to the security video and witness accounts, the man with a baseball cap, gray shirt and white pants parked next to the Cadillac Hotel, twice walking out to the boardwalk before getting into the Dodge Avenger and accelerating, swerving around yellow poles meant to prevent cars from getting into the pedestrian-only area and onto the boardwalk.
The man knocked over two mannequins then started hitting people, swerving from side to side and often running straight into them.
The crowd of hundreds of couples, families and children who had been sitting at cafes, shopping and walking lazily along in shorts and sandals were sent on a mad scramble to get themselves and others out of the way and to rush to help those who were hit.
The car hit at least three vendors who were sitting at their sales booths, video showed.
It hit two women who appeared to be in their 60s, Hagan said.
Many ran after the car, screaming and cursing as it sped away, he said.
Hodge said she and her friend, 31-year-old Ashley Taylor, had made note of the numbers walking along the seaside.
"It was a really nice day, there were tons of people out, in fact, we were talking about how packed it was, because we were having a hard time getting through all the people," said Hodge.
The Venice boardwalk is a cultural hub in a part of Los Angeles known for its circus-meets-gritty-city eccentricities.
The 1.5-mile ribbon of asphalt that runs along the sand a few hundred yards from the ocean is home to galleries, restaurants, tattoo shops, skateboard parks and the famous outdoor weight room known as Muscle Beach.
It can draw as many as 150,000 people on summer weekends.