In their ongoing battle against the city's entrenched gangs, prosecutors and the Los Angeles Police Department have relied increasingly in recent years on a favorite bureaucratic weapon: Court-ordered injunctions.

The injunctions aim to severely curtail gang activity by, among other things, prohibiting gang members from socializing with each other, carrying weapons and wearing certain clothing inside "safe zones" that typically encompass neighborhoods where the gangs are active. Those who don't comply can be arrested and charged.

A federal lawsuit filed earlier this month in Los Angeles, however, has taken aim at the nighttime curfews included in 21 of the 50 injunctions in effect within the city. The terms of the curfews, which prohibit going outside after 10 p.m., are so broad and vague as to violate a person's constitutional rights, said Olu Orange, the attorney behind the lawsuit.

The city, Orange said, has willfully ignored an appellate court ruling finding that similarly worded gang curfews violated people's due process rights. In that ruling, the California Supreme Court found that an injunction against an Oxnard gang did not adequately define what it meant for someone included in the injunction to be "outside" during the curfew hours.

The wording was "so vague that men of common intelligence must necessarily guess at its meaning," the court found.

The city's other gang injunctions also impose curfews but use wording that is more specific and less restrictive, Orange said.

A spokesperson for the city attorney's office could not be reached for comment.

The latest lawsuit stems from the arrest of Christian Rodriguez, a teenage boy who lives in the Mar Vista Gardens housing project –- a stronghold of the Culver City Boys gang.

Rodriguez is not a gang member, his attorney said, but was placed under the injunction because of an older brother's ties to the gang. LAPD anti-gang officers arrested Rodriguez late one night in June 2009 when they found him with friends at the housing project's handball courts. He was charged with violating curfew.

The criminal charges against Rodriguez were dropped, but Orange said a broader challenge to the curfews is necessary. Orange said he will try to have the case designated as a class action, which would allow anyone ever arrested for a curfew violation under the 21 gang injunctions to join the lawsuit. Beyond seeking a change to the wording of curfew clauses, Orange said he planned to argue that any person arrested for a curfew violation was entitled to compensation for having his or her constitutional rights violated.

The lawsuit is the latest challenge to gang injunctions. They also have come under fire by critics who say there is not an adequate process by which people can petition to have their names removed from injunction lists.

-- Joel Rubin

www.twitter.com/joelrubin