“I was a drug warrior until I saw what was happening in my own courtroom,’’ said Gray, a former federal prosecutor.

On-the-job experience demonstrated the futility of trying to enforce laws prohibiting the possession and use of small amounts of cannabis, Gray said at a news conference held by Law Enforcement Against Prohibition, a nonprofit organization supporting Proposition 19.

Beat police would have more time to go after burglars, robbers and those committing violent assaults, he said.

Proposition 19’s passage in November would decriminalize an estimated 60,000 drug arrests made in California each year, said former Orange County Superior Court Judge James Gray.

Legalizing marijuana would put a big dent in drug cartels and free up police, prosecutors and judges to go after violent crimes, a law enforcement group said Monday in endorsing Proposition 19, the marijuana legalization measure.

Current laws are making pot more readily accessible to youngsters than would be the case if it were regulated and taxed by the government, similar to tobacco and alcohol, Gray said.

Juvenile gangs use pot sales as a recruiting tool, he said. Gray was joined by former San Jose Police Chief Joseph McNamara in arguing that much of the money flowing to violent drug cartels comes from the illegal sale of marijuana.

Citing White House statistics, McNamara said 60% of cartel money stems from marijuana. Those who argue that a black market would remain aren’t paying attention to history, McNamara said.

After the prohibition on alcohol was repealed, bootleggers disappeared, said McNamara, now a research fellow in drug policy at Stanford University. Law Enforcement Against Prohibition, based in Massachusetts, was started in 2002 by five former police officers who viewed the war on drugs as a failure. Neill Franklin, a retired narcotics officer, recently took over as executive director.

[Corrected, 4:22 p.m.: An earlier version of this post incorrectly said Franklin formed the group.]

Proposition 19 would make it legal to grow, possess and use up to an ounce of marijuana for personal use. It would also permit state and local governments to regulate and tax retail sales for adults 21 and older. State officials estimate passage could generate up to $1.4 billion in new tax revenue per year.

Active law enforcement groups, including the California Police Chiefs Assn., are opposed to the measure, saying it would increase usage and promote crime. Gray, the retired judge, said he believes that many in law enforcement support legalization but are afraid to say so because of political pressure on the job.

“They have a political job, so they can’t tell the truth," Gray said. “People are free to speak out honestly only after they are retired.”

-- Catherine Saillant