The attacks happened Monday morning on Ocean Front Walk, according to the Santa Monica Police Department. It's unclear what provoked the alleged attacks.
The victims include a woman and a 17-year-old girl who was taken to the hospital with serious injuries. One of the victims was hurt trying to intervene, police said.
"He turned his attention towards me tried to strangle me ... bit the heck out of my ear and tried to dislodge my pants from their original resting position," she said.
The victims are all expected to be OK.
"He attacked a third victim who was a woman in her 70s and pulled her into the water and actually was holding her under the water when lifeguards arrived," said Santa Monica Police Lt. Erika Aklufi.
The homeless man was taken into custody shortly after and is now facing several felony charges. Monday's incident is just the latest attack along Ocean Front Walk.
Last month, a homeless man was arrested for trying to rape a young woman who was jogging on a beach path. Another homeless man was also arrested for assaulting a 73-year-old woman.
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"We are seeing in Santa Monica meth use, fentanyl use, lots of drugs that can have negative impacts on people's behavior. It does make them more aggressive," said Aklufi.
A massive sign hung by the Santa Monica Coalition that reads "Santa Methica Is Not Safe" was discussed Tuesday night at a city council meeting. The meeting was still in session late into the night.
According to the agenda, the point of contention is the language that says "Santa Monica City Manager supports free needle and meth pipe distribution in our parks and public spaces."
John Alle owns the building where the sign hangs from and says that despite an attempt to get it removed, it's not coming down. Alle says he was attacked by a homeless person last September and needed brain surgery.
"I grew up in this city. I would ride my bike to the Promenade, to the tennis courts, and I couldn't have my son do that today. It's very unsafe," he said.
Despite protests in April, Los Angeles County has been operating an open air, publicly funded needle distribution program as part of its harm reduction programs.
"We're OK with the harm reduction program," Alle said. "We just want it moved out of the parks."