The U.S. Supreme Court stunned California on May 23 when it ruled that the state must depopulate its overcrowded prison system by tens of thousands of inmates.

The decree, written by Californian Anthony Kennedy, reignited the state's perennial debate over crime's causes, effects and remedies.

While liberal critics of the state's criminal justice system hailed it as a long overdue wake-up call for reform, conservatives raised the specter of felonious hordes being released to prey upon the public.

A day later, California Attorney General Kamala Harris announced that the state's rates of homicide and other violent crimes had continued a decades-long decline. She said it "reflects the tireless efforts of our peace officers" and pledged support for "their brave, relentless and selfless work in protecting the people of California from hardened criminals."

So, have California's crime rates fallen because the state adopted a get-tough attitude three decades ago and began locking up more of its miscreants?

The prison population surged from about 20,000 to more than 160,000 during that period as sentencing laws were beefed up, symbolized by the passage of the state's "three strikes and you're out" statute.

Supporters of the crackdown credit "three-strikes" and other sentencing laws for the steady drop in crime. Harris' remarks appear to support the view that when cops and prosecutors crack down, criminals retreat and the public is safer.

But to Robert Parker, a professor at the University of California, Riverside, that's just hot air.

As the Supreme Court was issuing its ruling and Harris was announcing a decline in violent crime, Parker was circulating his new study contending that three-strikes and other sentencing laws had virtually nothing to do with the state's decreasing violent crime rate.

Citing "logic, data and research," Parker contends that "all these uniformly show little or no impact of three strikes policy on violent crime rates in California and elsewhere."

He compared historic crime patterns in California and other states with similar laws to those without such laws and found they "show little difference in … pattern of violent crime."

Parker cites other studies that attribute crime rate declines to economic and social factors, such as alcohol consumption, rather than policing and sentencing policies and suggests it's "better to use alcohol policy to control violence than three strikes."

Were California to change its approach to crime and comply with the federal court order to reduce the prison population, he notes, it could save $2.3 billion a year in prison costs.

"California needs to stop gorging itself at the all-you-can-eat buffet of imprisonment," says Parker.

His study, if nothing else, provides new fuel for the ever-burning crime debate.

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