The Justice Department is dispatching teams of federal agents to 15 cities struggling with violent crime problems despite a dropping U.S. crime rate, Attorney General John Ashcroft (search) said Thursday.

Ashcroft told reporters that the effort would be targeted at "the hottest zones of criminal activity" in cities where high murder and violence rates persist despite a violent crime rate that is at a 30-year low nationwide, based on federal victimization statistics.

The initiative also is aimed at reducing the traditional summer increase in murder and violent crime, he said. Firearms offenses are the main focus because they are often more readily proven in court than other crimes.

"We hope this will be successful early -- that this summer will be a different kind of summer," Ashcroft said.

Teams of agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives (search); U.S. Marshals Service (search); FBI (search); and Drug Enforcement Administration (searchwill be assigned to each of the 15 cities for six months. A Justice Department prosecutor will handle cases of those charged.

Investigators will focus on prosecuting people for firearms violations, which often accompany gang activity, illegal drug organizations and organized crime groups. The 15 Violent Crime Impact Teams will use high-tech surveillance and other techniques to identify the worst offenders.

The ATF is leading the effort because of its expertise in gun crime investigations and ballistics, said ATF Director Carl Truscott.

Concentrating on gun crimes allows prosecutors to "focus on the thugs who are plaguing these neighborhoods" and are likely responsible for a long list of other offenses, said Deputy Attorney General James Comey.

Ashcroft said the initiative also will bring other federal charges where evidence warrants and assist state and local authorities in their criminal cases against the same offenders.

The 15 cities are Albuquerque, N.M.; Baltimore; Chattanooga, Tenn.; Tampa, Fla.; Miami; Richmond, Va.; Greensboro, N.C.; Tulsa, Okla.; Pittsburgh; Las Vegas; Columbus, Ohio; Philadelphia; Los Angeles; Tucson, Ariz.; and the Washington, D.C.-Northern Virginia region.