DOWNEY (CBSLA) – A now 20-year-old man who was involved in the 2015 slaying of a Downey police officer and Marine veteran during a botched robbery could be released from jail in the next few years because of a new state law which came under fire Tuesday night at a Downey City Council meeting.

Abel Diaz and two half-brothers were arrested in connection with the Nov. 18, 2015, killing of 29-year-old Downey police officer Ricardo Galvez.

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Downey police officer Ricardo Galvez.

Galvez was shot once in the face while sitting in his BMW in a parking lot near his police station. Galvez had served two tours of duty — one in Iraq and one in Afghanistan — in the Marine Corps prior to becoming a police officer.

Last month, Diaz admitted in juvenile court to one count each of murder, robbery and attempted robbery in Galvez’ killing.

Diaz, who was 16 at the time of the killing, was initially charged as an adult. However, his case was transferred to juvenile court as a result of Proposition 57, approved by voters in 2016.

The uproar Tuesday night was over the fact that Diaz could potentially be released from prison by the time he is 23-years-old because of a new law which took effect Jan. 1.

Under Senate Bill 1437, which was signed by former Gov. Jerry Brown last September, prosecutors are limited in whether they can charge an accomplice with murder. Under the law, prosecutors are prohibited from charging a suspect with felony murder “unless the person was the actual killer” or “aided” with the “intent” to kill.

Diaz was armed at the time of the robbery but did shoot Galvez, investigators say. In other words, if Diaz did not pull the trigger and had only intended to rob Galvez, he cannot be charged with felony murder in the case under Senate Bill 1437.

Critics of the law argue it is letting violent criminals off too easy.

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“Mr. Diaz was not some innocent kid, caught up in the moment, and an accident occurred,” Downey police Capt. Mark McDaniel told the City Council Tuesday. “He actively participated, with even his face partially covered to hide his identity, in the murder of Ricky. How in the world can Mr. Diaz be released out into our community in the next few years? It’s really unbelievable.”

Cpl. Ralph Diaz, the current Downey Police Officer Association president and Galvez’s best friend at the time he was shot, told CBS2 Tuesday there is discussion about a potential lawsuit against the state of California to have the law overturned.

“The hope is to have it changed,” Diaz told CBS2 outside the meeting. “And if we can’t have it completely overturned, at least meet somewhere in the middle.”

“As long as I’m alive, I will never let Ricky’s memory die and I will never let this Senate bill go down,” Diaz added.

The other two suspects, 21-year-old Steven Knott and 24-year-old Jeremy Anthony Alvarez, are awaiting trial in connection with the killing. Prosecutors have not yet decided whether to seek the death penalty against them.

Alvarez — the alleged getaway driver — was arrested after a wild pursuit. Knott and Diaz were arrested the morning after the shooting.

Investigators subsequently recovered a handgun that was allegedly thrown out of the Nissan Altima while Alvarez was behind the wheel.

Prosecutors say ballistics tests determined that the gun had been used to kill Galvez. DNA testing and fingerprint analysis linked Knott to the weapon, according to stipulations agreed to by the prosecution and the defense at last year’s preliminary hearing.

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)