A man suspected of killing a Whittier police officer in a shootout Monday, hours after slaying his cousin, was arrested five times in the past seven months while under supervision of county authorities as part of a controversial program many law enforcement agencies blame for an uptick in crime, according to records and authorities.

Michael Christopher Mejia, 26, of Los Angeles, was identified Tuesday as the suspect in the fatal shootings of Whittier police Officer Keith Boyer and 46-year-old Roy Torres, the suspect’s cousin.

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Lt. John Corina of the Los Angeles County Sheriff’s Department Homicide Bureau said Mejia was released from state prison in April 2016 following a grand theft auto conviction in 2014. He was on county probation under Assembly Bill 109 when he allegedly shot and killed Boyer and Torres and had been arrested multiple times in recent months for violating his probation, Corina said.

Signed into law in 2011, AB 109 mandated “realignment,” which shifted nonviolent offenders from state prisons to county jails, or placed them on probation under county supervision rather than parole under state supervision. It was a response to a U.S. Supreme Court order declaring the condition of California’s overcrowded prisons as violating the constitutional rights of inmates.

Mejia is suspected of fatally shooting Boyer, 53, and wounding his partner Officer Patrick Hazell in a shootout that began around 8 a.m. when the two officers responded to a traffic collision at Mar Vista Street and Colima Road.

Authorities said the suspect rear-ended two vehicles stopped at the intersection while he was driving the car he stole from Torres hours earlier.

When officers arrived and contacted the suspect, Corina said Mejia pulled out a hand gun from his waistband after exiting the car and shot at both Boyer and Hazell, striking both of them. Mejia was also struck during the brief gun battle.

Mejia is suspected of also fatally shooting Torres a few hours earlier in the 1400 block of Volney Drive before stealing his car.

Related: Suspect in death of Whittier officer also shot cousin in East L.A. home, family says

In 2010, Mejia was convicted of robbery and sentenced to four years in prison, according to court records. His 2014 conviction came with a two-year prison sentence.

Since being released last year, Mejia has been arrested five times for probation violations, Los Angeles County booking records show. His most recent arrest was on Feb. 2.

In each case, no charges were filed and Mejia was held for a period of nine or 10 days before being released.

Corina said he was not sure what the probation violations were, referring to the temporary holds as “flash incarcerations.”

Flash incarcerations are used as punishment for violations of probation, ranging from minor offenses to more serious crimes, according to Kerry Webb, spokeswoman for the Los Angeles County Probation Department. Webb could not speak specifically to Mejia’s case because of confidentiality laws.

“It’s temporary for the most part, to basically get them off the street,” she said.

A flash incarceration might imprison a low-level drug offender for up to 10 days, for example, and then release the individual into drug rehabilitation. But it could also be used on someone with a more serious violation ahead of a judge’s ruling on his or her probation status, Webb said.

“At some point, the court will get involved and take a look at what is going on here and see the pattern,” she said. “The judge will have to make a final decision.”

Someone with repeat violations is more likely to get elevated to those harsher consequences, she said.

A probationer under AB 109 is sent to the county’s supervision for non-violent, non-serious and non-sexual offenses. Webb said AB 109 eligibility is based on the offense the person is in jail for, not their prior record, but ultimately, a judge determines whether each person qualifies.

Mejia, who was still being treated at a local hospital Tuesday, has not been charged in either of the Monday killings. Corina said investigators have not yet interviewed the suspect, adding that they would likely submit the case to the Los Angeles County District Attorney’s office next week.

Staff writer Jason Henry contributed to this report.