LOS ANGELES, Calif. -- A "violent predator" arrested on suspicion of carrying out a string of attacks against seven mainly homeless men in Southern California, brutally beating them and killing three, also faced investigation in the disappearances of two of his relatives in Texas, authorities said Tuesday.

Ramon Escobar, 47, who was believed to be homeless himself, likely targeted his victims to rob them, Los Angeles police Capt. Capt. William Hayes told reporters.

Hayes called Escobar a "violent predator" and said investigators believe he drove to California from Houston and attacked the men in Los Angeles and Santa Monica beginning Sept. 8, Hayes said.

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CBS Los Angeles reports that police recovered a wooden baseball bat and a pair of bolt cutters from Escobar's car that are believed to have been used in the attacks.

"I think it was a crime of opportunity," Hayes said. "... It appears the motive in most of these cases was robbery."

Escobar was arrested Monday in the Los Angeles suburb of Santa Monica after a man sitting on a sidewalk was beaten unconscious and robbed of some of his possessions, police said. That victim remains in coma.

Police will ask prosecutors Wednesday to charge Escobar with three counts of murder and four counts of attempted murder, officials said.

He's being held without bail, and it wasn't immediately known if he has an attorney who can speak on his behalf.

Escobar is a person of interest in the disappearances late last month of 60-year-old Dina Escobar and her brother, 65-year-old Rogelio Escobar, Houston police said in a statement.

Dina Escobar's burned van was found in Galveston, Texas, a few days after she went looking for her brother. She was last seen Aug. 28, two days after her brother disappeared, the statement said.

Ramon Escobar is their nephew, and Texas authorities said they want to talk to him.

Dina's daughter, Ligia Salamanca, spoke to CBS affiliate KHOU-TV on Tuesday.

"The detectives called me last night wanting me to know before I saw it on the media that there has been an arrest made of a family member and it may be connected to our case" Salamanca said.

She told KHOU-TV that she's heartbroken, but feels better having some answers.

"The not knowing is the worst, going to sleep every night not knowing where your family is, what their going through or if something bad happened; not having them at home to know what they're going through – to lay them to rest if that's what it comes to," she said.

Ramon Escobar KHOU-TV

Escobar spent five years in prison for robbery starting in the mid-1990s, Hayes said. Records in Texas show Escobar has had arrests for vehicle burglary, trespassing, failure to stop, public intoxication and two assaults, most recently in November 2017. That case was described as a misdemeanor.

Investigators believe Escobar was the man who used a baseball bat to bash the heads of three homeless men sleeping on downtown Los Angeles streets before dawn on Sept. 16, police said in a statement. Two died.

He was recorded on surveillance video ransacking their pockets and belongings.

Two homeless men sleeping on the beach were bludgeoned in the head early on Sept. 8 and Sept. 10, leaving one in critical condition, officials said.

Another man who apparently was sleeping on the beach was found dead under the Santa Monica Pier on Sept. 20. Steven Ray Cruze Jr., 39, of San Gabriel, had been beaten to death.

Authorities at first described him as homeless, but family and friends said the father of two, who loved to fish at the pier, worked boats in neighboring Marina del Rey and sometimes camped out under the pier to avoid the long commute home.