Prosecutors and police officers from across the state pleaded with legislators Tuesday for tougher anti-gang laws, saying they want to define who is a "gang member" and broaden the number of crimes that trigger longer prison sentences.

Law enforcement groups told the House Judiciary Committtee that the Maryland Gang Prevention Act, enacted two years ago to stiffen penalties for gang members, isn't working because it fails to define "gang member," doesn't include enough gang-related crimes and carries no mandatory prison time. While it was used as leverage in one guilty plea in Prince George's County, no one has been successfully prosecuted under the act.

"The statute is very hard to use because of its ambiguous language," said Baltimore State's Attorney Patricia C. Jessamy, who is leading the push for tougher anti-gang laws. "We find ourselves defending the law more than using it."

Civil liberties groups and public defenders are opposing new anti-gang legislation, which they say would fill already crowded state prisons at a time when legislative analysts have suggested reducing incarceration as a cost-cutting measure. They say prevention and intervention are more effective ways to combat gangs.

Criminal code revisions frequently are blocked in the Judiciary Committee, which includes several practicing defense attorneys and has been reluctant to take sentencing discretion away from judges or broaden categories of crime.

But prosecutors and police have a powerful ally this year: House Speaker Michael E. Busch.

Busch, an Anne Arundel County Democrat who has gang legislation of his own up for debate today, sat in on the committee hearing, in part to send a message to the delegates.

"I would hope the committee could find a way to make something work," he said. "This is a very real issue. What we're hearing from our prosecutors is that federal prosecutors have tools, whereas [state prosecutors] don't have the ability to try these gang cases."

Lawmakers are considering dozens of anti-gang measures, but much of the hearing Tuesday focused on Del. Gerron S. Levi's proposed revision of the existing gang prevention act.

The Prince George's County Democrat said that if police and prosecutors "do the extra work" of proving who is a gang member, judges should give those defendants up to 20 years of extra prison time.

All 24 chief state's attorneys opposed the 2007 law, which they considered too weak. It gives judges authority to impose additional time behind bars, but also lets them assign it to run at the same time as other sentences.

Levi said her bill "closes those loopholes."

Aides to Gov. Martin O'Malley, who signed the 2007 anti-gang act, have also been working to strengthen the law. Maryland State Police Superintendent Col. Terrence B. Sheridan and Public Safety Secretary Gary D. Maynard testified in favor of Levi's and other proposals.

Prosecutors and police say they need state law to spell out who is a gang member because each county and the city defines it differently, which makes it difficult to develop a unified approach to combating gangs.

Levi said her gang prevention act would be activated only if a known "criminal gang member" has been convicted of at least two underlying crimes, such as assault, murder or witness intimidation. She also wants to add some misdemeanors, such as destruction of property, to the list of qualifying crimes. To determine who is a "criminal gang member," prosecutors would have to prove at least two of five criteria.

In practical terms, this would mean a defendant could qualify for enhanced penalties if he or she has been convicted of two crimes spelled out in the law, declares him- or herself a gang member and associates with other known gang members.

Advocates say the provisions mean that only gang leaders would be targeted, not casual teenage members or first-time offenders.

But some of the committee members expressed skepticism about the sweep of Levi's proposal.

Del. Victor R. Ramirez, a Prince George's County Democrat, questioned the need for enhanced penalties for gang members because people are already being prosecuted for underlying crimes.

Del. Joseph F. Vallario Jr., a Democrat who is the committee chairman, said the definition of a gang member troubles him. "Everybody and their brother fits this description," he said, and added that even members of a local VFW could be labeled gang members. His comments prompted Republican Del. Don H. Dwyer Jr., a co-sponsor of Levi's bill, to exclaim, "You see? This is why we never get anywhere on this committee."

More than half of the 22 members of the House Judiciary Committee - including the chairman and vice chairman - are listed as attorneys in the Maryland Lawyers' Manual. Over the years, committee members have resisted strengthening drunk-driving laws and other tough-on-crime legislation.

Levi's plan was one of many debated Tuesday. Other ideas include making it easier to prosecute young gang members as adults rather than juveniles, eliminating good-time credit for gang members behind bars and developing a gang leader criminal category that mirrors Maryland's drug kingpin statute.

Cindy Boersma, director for the American Civil Liberties Union of Maryland, said the proposals "are all aiming in the wrong direction."

They're based on a "skewed or inaccurate assessment of the reality of gangs and gang crimes," she said, because gang members are responsible for a small fraction of crimes in the state. She said national research shows that gang problems are not worsening.

Prosecutors and police begged to differ. "All of us could sit up here and tell you story after story," said Scott D. Shellenberger, Baltimore County's state's attorney. He said he had to cede authority to federal prosecutors when Patrick Byers killed Carl Lackl, a witness in a murder case, as part of a gang initiation.

"We don't have the tools to prosecute," he said.

Busch said his interest in gang legislation intensified after the high-profile gang-related killing of a 14-year-old Crofton boy last summer. The boy's parents contend that the Anne Arundel school system did not do enough to prevent gang activity.

The House education committee today will hear Busch's proposal to increase communication between schools and police when either suspects gang activity.

Who is a gang member? Del. Gerron S. Levi's proposal would define a member as someone who fits at least two of these categories:

•You proclaim yourself a member

•You use a gang's name, sign or symbol

•You associate with other known gang members and demonstrate aspiration to become a member by adopting style of dress, tattoos or hand signals or participate in gang activities

•The prison system has determined you are a gang member

•Photos or electronic communication provide evidence of your gang membership