Jerrid Powell, 33, is behind bars accused of killing the men as they slept on the streets of the city, and of murdering a fourth victim during a home invasion robbery.
He received the cash settlement from the City of Santa Monica over a 2019 incident in which he was injured when a beach patrol officer responding to a fire ran him over. Officials say that he was lying down in a ditch in the sand at the time of the incident.
“The City settled the lawsuit claiming negligence after a Santa Monica Harbor Services Officer, after responding to a call reporting a fire on the beach, rolled over the plaintiff who was laying in a six to eight-inch-deep ditch in the sand,” a city spokesperson told Fox News.
Mr Powell used the settlement money to buy a gun and the car used in the murders, law enforcement sources told the outlet.
The Los Angeles District Attorney’s Office said in a statement that Mr Powell has at least one prior felony conviction and could not legally own or buy a gun.
He also was charged with theft while on probation for a 2018 assault with a deadly weapon conviction, according to NBC Los Angeles.
Mr Powell is accused of killing the homeless men in separate shootings in the Los Angeles area last month.
He also allegedly killed county employee Nicholas Simbolon after following him to his home in San Dimas, California, from an electric vehicle charging station.
Police say the victim was found by his wife dead inside his Tesla vehicle that was parked in their garage.
The suspect was arrested by police in Beverly Hills on 30 November after his BMW was linked to the killing.
Investigators then matched a handgun found inside the vehicle to the homeless killings, according to Los Angeles Police Chief Michel Moore.
Mr Powell faces four counts of murder, robbery and being a felon in possession of a firearm.
He also faces special circumstances of allegedly committing multiple murders and murder in the course of a robbery, as well as suspected personal use of a firearm, the DA’s office said.
A formal arraignment and plea hearing has been scheduled for 8 January.