When Gov. Jerry Brown was promoting Proposition 57 to voters in 2016, he characterized it as a common sense criminal law reform that would give nonviolent felons a better chance at rehabilitation by allowing them to earn earlier releases on parole.

However, it did not specify which felonies would be deemed nonviolent. Rather, Brown’s campaign confirmed that it would be every felony not included on a specific Penal Code list of 23 violent crimes – and that lack of specificity is now backfiring.

Indirectly, leniency would be allowed for quite a few felonies, such as sex crimes, that most of us would deem to be violent – and, in fact, are counted as violent offenses in crime data provided by the state Department of Justice.

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Critics of Brown’s measure – the state’s prosecutors, particularly – pointed out the anomaly, and complained that if passed, it could allow some vicious predators to once again range freely.

In response, Brown publicly promised that by regulation, state prison officials would make sure that sex criminals would not benefit from Proposition 57’s new leniency and voters apparently believed him, because they passed the measure.

The promised regulations restricting parole for some sex crimes were, in fact, published by the California Department of Corrections and Rehabilitation (CDCR).

However, attorneys for the Alliance for Constitutional Sex Offense Laws and one “John Doe,” who had been imprisoned for lewd acts with a 14-year-old, challenged the rules, saying they violated Proposition 57’s more lenient parole opportunities.

Proposition 57’s ban on early parole, they contended, was implicitly limited to 23 violent felonies of Penal Code Section 667.5, but the department’s new rules extended the ban to sex offenses under PC Section 290, thereby violating the measure.

Last week, Sacramento County Superior Court Judge Allen Sumner declared his intention to rule for the plaintiffs and overturn the rules.

“The court agrees the challenged regulations are overbroad and must be set aside,” Sumner wrote. “But the court does not direct CDCR to adopt any particular replacement regulations. Instead, the court remands this case to CDCR to adopt new regulations defining the term ‘nonviolent felony offense’ consistent with this ruling.”

In essence, Sumner is not only agreeing with John Doe, but also with the prosecutors who opposed Brown’s measure in 2016, arguing that as written, it could require granting lenience to those who commit serious sex crimes.

While the measure gives CDCR authority to issue implementing regulations, Sumner wrote, “CDCR’s definition must comport with some colorable meaning of the term ‘non-violent felony.’ It does not.”

Brown’s prison agency must now either rewrite the regulations, presumably to provide more leniency to John Doe and other sex criminals, or try to overturn Sumner’s ruling on appeal.

The latter course is more likely, because rewriting the rules would, in effect, concede the issue to the prosecutors who criticized Proposition 57 as too vaguely drafted and too broad.

“We repeatedly warned prior to the election that the ambiguities of language in Prop 57 would allow sex offenders to be released early from prison,” the Association of Deputy District Attorneys said after Sumner’s ruling. “The proponents realized the public wouldn’t support that, so led by Gov. Jerry Brown they responded by promising that CDCR would write regulations to make sure sex-offenders weren’t released early.”

“We knew that approach would fail,” the ADDA continued, “because a regulation cannot expand the scope of the law that it purports to implement. Now, the completely foreseeable result of this poor drafting has occurred.”

Were John Doe and several thousand other predatory sex criminals to waltz free despite Brown’s campaign assurances, it also would put a stain on what he clearly hopes will be a legacy of criminal justice reform.