Los Angeles Police Chief Charlie Beck joined other law enforcement leaders in Washington on Wednesday to slam Arizona's crackdown on illegal immigration, saying it could cripple police work and drive a wedge between officers and the communities they are trying to protect.Beck has emerged as a leading critic of a new law that will make it a state crime to be in Arizona illegally and will require police to check suspects for immigration paperwork. In a conference call with journalists after he and other police officials met with U.S. Atty. Gen. Eric Holder, Beck said "legislation like this inhibits us from doing our jobs" and will dissuade immigrants from coming forward as victims and witnesses.

Los Angeles Police Chief Charlie Beck

"The fear of the police already inhibits immigrants from coming forward to a certain extent," he said. "But if you add this piece you increase the reluctance tenfold."

"People should remember that undocumented immigrants are witnesses in all kinds of crime and this does not just affect them," Beck said. "If people don't come forward to help the police solve and protect crime, no matter what their status, then we are doomed to failure. It threatens to destroy a lot of the work that has been done."

Beck said that his officers are guided by a different set of rules than the ones laid out in the Arizona law. For more than three decades the LAPD has followed a policy that prohibits officers from initiating contact with someone solely to determine whether he or she is in the country legally. Beck and police chiefs from other cities, including Phoenix, Tucson, Philadelphia and Houston, told Holder they hoped for a federal solution to the immigration problem.

"The primary job of a local police department is not the enforcement of immigration status," Beck said. "The primary job of law enforcement is to protect the public and keep us free from crime."

During the hourlong meeting, Holder told the officials that a federal challenge to Arizona's law may be imminent, according to participants.

"He did say that the Justice Department is seriously considering action and that it could be done soon," said Chuck Wexler, the director of the Police Executive Research Forum.

Holder has previously expressed dismay over Arizona's new legislation, calling it "an unfortunate one.... It is, I fear, subject to potential abuse," Holder said.

Justice officials have said that they may challenge the law on two grounds - for subjecting people to racial profiling and for usurping the federal government's power to enforce immigration law.