HOUSTON - The nephew of siblings who went missing last month in Houston has been arrested after a string of violent attacks in California and identified as a person of interested in his aunt and uncle's case.

Detectives say Ramon Escobar, a nephew of missing brother and sister, Roy and Dina Escobar, has been arrested in California for the beating deaths of two homeless men.

He faces three murder charges and four attempted murder charges after a string of attacks on homeless victims in California, authorities said Tuesday.

TIMELINE: Houston siblings' disappearance, nephew named person of interest

"He's a violent predator. He's preying on innocent people," said Cpt. William Hayes with the Los Angeles Police Department. "In particular, in most of these cases, our victims were asleep, and he went up and did it. As I indicated, he's a violent predator who I question why he would do it...and I don't know why."

Investigators said they don't believe Ramon Escobar's motive is beyond robbery for these alleged crimes in California.

The Escobar siblings have been missing since the end of August.

Authorities found a torched van in Galveston days after they were reported missing. They say the van belonged to Dina. Investigators say Ramon Escobar was questioned in Houston after police discovered the van. He left shortly thereafter to California in his own car, police said.

So far, searches for the siblings have come up empty.

On Tuesday, Dina's daughter Ligia Salamanca spoke to KHOU 11 News.

"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.

The relative the detective was referring to is Escobar. Los Angeles police have described him at a violent predator.

So far he's been charged with two counts of murder and one count of attempted murder.

"It give me a fear of what happened to my mom and my uncle." Salamanca said.

She said her suspicions about her cousin's involvement were there - he hadn't been present during any of the searches and he had been living with her uncle.

"He was there at the house both days when my mother and when my uncle went missing." she said.

She says while heartbroken that her heartache may have been caused by a close relative, she says she feels better knowing she may soon have 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 is expected to face a judge Wednesday in California. It is unclear at this time whether he will be brought back to Houston for questioning or to face a judge.