Updated 5:23 p.m.
LOS ANGELES Before a black Dodge Avenger careened down the crowded Venice Beach boardwalk last weekend, and killing an Italian newlywed, suspect Nathan Louis Campbell left virtually no evidence of his short presence in Southern California.
The 38-year-old had no fixed address and no state driver's license, and police have found no evidence he was working.
(Warning: Viewers may find some of the video at left disturbing)
Investigators believe Campbell, who was arrested for investigation of murder after he walked into a police station several hours after Saturday's rampage, was driving his own car, Los Angeles police Cmdr. Andrew Smith said.
"I think we can safely say, when he turned himself in ... he implicated himself in the Venice incident," Smith said.
Police have not yet presented their case to prosecutors, who planned to file charges Tuesday, when Campbell could also appear in court.
Investigators have yet to provide an explanation why the driver maneuvered around a vehicle barrier early that evening and plowed into tourists and vendors along the fabled walkway bordering the Pacific,.
Her new husband, Christian Casadei, was at her side. He suffered minor injuries.
In a statement Monday, Casadei called his wife "an immense gift: a gift that no one can ever understand. She gave happiness and joy to anyone who had the luck to know her.
"About our love, you cannot say more than it will remain a dream from which we will never wake," he said.
CBS Los Angeles reported a fundraiser and vigil was held for Gruppioni on the Venice Beach Boardwalk Monday.
One person was critically injured and two others were taken to hospitals in serious condition. The 13 others all received less severe injuries.
Little is known about Campbell, who is being held on $1 million bail. No relatives or close friends have emerged since the incident to talk about him, and police have revealed scant details.
Campbell appears to have deeper ties to Colorado, where he lived as recently as last year. He was evicted from his apartment in Denver for not paying $655 in rent in March 2012, records show.
He was sentenced to five days in jail afterat a Denver supermarket in February 2009. Five months later, he was accused of trespassing at an outdoor mall in Denver and sentenced to 10 days in jail, court records show.
Police said Campbell initially parked outside a hotel and surveyed the boardwalk, where hundreds of people were sitting at cafes, walking along the seashore or shopping for jewelry, art or other items at vending stands.
Surveillance video showed a driver getting into the Dodge, steering around a vehicle barrier and careening through the crowd.
Two mannequins and an ATM were knocked down as the car started hitting people. It swerved from side to side, hitting vendors, jewelry sellers, a fortune teller and a tattoo artist.
Witnesses said the car was traveling at least 35 mph. It later turned up on a side street less than 2 miles away.
An autopsy by the Los Angeles County coroner concluded Gruppioni died from blunt-force trauma to the head and neck. Her death has been classified as a homicide.
A makeshift boardwalk memorial for Gruppioni continued to grow Monday, with mourners placing a note in Italian expressing condolences and a painting that reads, "Venice loves you, Alice."
Gruppioni was a general manager for the family business that makes radiators. Her father, Valerio Gruppioni, runs the company and was formerly president of the Bologna soccer team, according to Italian news agency LaPresse.
Gruppioni's aunt said that hours before her niece was killed, she shared stories of her honeymoon travels by phone with her parents in Italy.
"She was beyond happiness," Katia Gruppioni said.
Gruppioni's family described her as a devoted businesswoman with a romantic side, who never stopped dreaming about her bridal gown and meeting Prince Charming.
"She was robbed of her life while living her dream visit to California with her husband and this was a tremendous injustice," the family said in a statement.
The Los Angeles City Council also unanimously approved Tuesday a motion that asks police and city officials to immediately erect temporary barriers at the most dangerous intersections along the boardwalk in order to prevent cars from getting in.
The council also asked for a two-week study that will assess where to install permanent posts or other barriers to keep cars away from pedestrians.