Possession of small amounts of marijuana will no longer be a crime in Maryland under a law passed Monday and sent to Gov. Martin O'Malley for his expected signature.

Adults caught with less than 10 grams of pot will get a citation that will be treated like traffic ticket and pay a fine, but they could no longer be sent to jail. O'Malley said he plans to sign the law, a reversal from views he held as he gained prominence as Baltimore's tough-on-crime mayor.

"As a young prosecutor, I once thought that decriminalizing the possession of marijuana might undermine the public will necessary to combat drug violence and improve public safety," O'Malley said in a statement. "I now think that decriminalizing possession of marijuana is an acknowledgment of the low priority that our courts, our prosecutors, our police, and the vast majority of citizens already attach to this transgression of public order and public health. Such an acknowledgment in law might even lead to a greater focus on far more serious threats to public safety and the lives of our citizens.”

More than a dozen other states have already decriminalized possession of small amounts of marijuana, as advocates push to treat minor drug offenses as a public health issue and not a crime.

Advocates mobilized this year to stop criminalizing minor pot offenses, joined by the NAACP and the ACLU in arguing that marijuana possession laws are unfairly applied. They pushed studies showing African-Americans who use marijuana are twice as likely to be prosecuted for the offense than their white counterparts.

The argument gained traction this year as key Democrats vying for governor embraced the idea, including Lt. Gov. Anthony Brown. The Senate measure was sponsored by Sen. Robert A. Zirkin, a Democrat from Baltimore County.

As recently as Friday, the proposal seemed to be dying in the House of Delegates, before the Legislative Black Caucus and other advocates convinced a key committee chairman to change course.

Advocates for the proposal argued that not only was the law enforced in a discriminatory way, the state had already rolled back penalties for possession so much that the justice system and courthouses were needlessly bogged down by minor marijuana offenders likely to be given probation.

The House of Delegates passed the proposal Saturday with just seven votes to spare, and opponents argued that decriminalizing possession sent the wrong message about drug use.

The Senate voted 34-8 Monday to adopt some changes made by the House.

Immediately after the vote, Brown, who is running for governor in the Democratic primary, praised the decision to lessen enforcement of possession.

“Our State's current marijuana laws are costly, ineffective, racially biased, and they result in a permanent blot on the records of too many of our young adults," Brown said in statement. "By decriminalizing the possession of small amounts of marijuana, we will be able to put our law enforcement resources where they belong: going after the real and violent crime in our communities."

The legislation would treat the first and second conviction of possession of 10 grams or less of marijuana by adults over 21 in a manner similar to a traffic ticket.

The fines would be $100 for a first offense and $250 for a second, and could be prepaid without a court appearance. On a third offense, the defendant would have to appear in court and would face a $500 fine and the possibility of bring required to go into drug treatment.

People 18 to 20-years-old who are caught with marijuana would have to go to court even for a first violation. The judge could refer them to a drug education course or assessment for possible treatment.

Those under 18 would continue to be dealt with through the criminal justice system.