After fatal shootings, officials try to find a reason for the violence

A SWAT team arrives at the area in Auburn where Placer County Sheriff's Det. Michael David Davis Jr. and Deputy Jeff Davis were shot Saturday. Jeff Davis was wounded in the arm; Michael Davis later died. The two lawmen are not related.

Oct. 26, 2014 9:21 PM PT

The survivor of a shooting rampage that killed two Northern California sheriff’s deputies remained hospitalized Sunday as authorities searched for a reason for the violence.

“We are no closer to determining a motive for any of this at this time,” Sacramento County Sheriff’s Sgt. Lisa Bowman said in an email. “The detectives are still working diligently in interviewing witnesses and collecting (and reviewing) evidence at all scenes to help piece this together.”

Luis Enrique Monroy Bracamonte, 34, who is in the United States illegally and was twice deported, was booked on suspicion of murder, attempted murder and carjacking after the fatal shootings of deputies in Sacramento and Placer counties on Saturday. His wife, Janelle Marquez Monroy, 38, was booked on suspicion of attempted murder and carjacking. Authorities say she was with her husband during much of Friday’s six-hour rampage.

The attacks began when Sacramento County Sheriff’s Deputy Danny Oliver, who was on patrol with his partner, stopped to check on a suspicious vehicle in a Motel 6 parking lot. Officials said Monroy fired from the car, fatally wounding Oliver, a 47-year-old father of two.

The couple then tried to carjack a motorist about a mile away, authorities said. When the driver, identified as Anthony Holmes, refused to turn over his keys, he was shot in the head.

On Sunday, Holmes was still hospitalized in fair condition. Bowman said he was not yet well enough to speak with detectives.

After failing to commandeer Holmes’ vehicle, officials said, the couple stole another car and drove to Auburn, where they were confronted by Placer County Sheriff’s Det. Michael David Davis Jr. and Deputy Jeff Davis. Authorities say Luis Monroy shot both lawmen.

Jeff Davis was wounded in the arm and Michael Davis, 42, later died. The officers are not related.

Monroy was later arrested in a residence.

The suspect was deported to Mexico in 1997 after his arrest and conviction in Arizona for possession of narcotics for sale, according to U.S. Immigration and Customs Enforcement. He was arrested and sent back to Mexico a second time in 2001.

On Sunday, a federal official who spoke on the condition of anonymity said it appeared that the 2001 arrest did not result in a second conviction of a crime.

Sacramento County Sheriff Scott Jones told the Sacramento Bee that Monroy may have lived under multiple identities and that he may have had troubles with the law under another name.

“We’re not convinced we have a full picture of his identity,” Jones told the newspaper. “Immigration has come up with one identity. We are not entirely convinced that is his only identity.”

The Times has reported that the suspect’s father-in-law, Mauro Marquez, always knew him as Luis Monroy and said his son-in-law was a house painter.

Dena Erwin, a spokeswoman for the Placer County Sheriff’s Department, said the agency is struggling to cope with Davis’ death.

“Everybody is numb at this point,” she said. “We have the funeral this week. Everybody is dealing with the reality of Mike not being in the office anymore.”

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The Associated Press contributed to this report.