CRIMINALS who strap on weapons each day in Baltimore and Prince George's County must now reckon with U.S. Attorney Thomas M. DiBiagio and Project Exile, the sharply focused antigun program that has worked well in Richmond, Va., and elsewhere.
Mr. DiBiagio's conversion to the belief that federal power is needed at the local level will surely be welcomed by Gov. Robert L. Ehrlich Jr., who had urged Mr. DiBiagio to get involved.
Under Exile's provisions, Mr. DiBiagio will take "well-developed cases" of gun possession involving suspects with prior violent felony or drug convictions.
These defendants would be tried by federal judges before federal juries. They might be denied bail.
And if convicted, they would serve at least five years in prisons far from Maryland - hence the term "Exile."
Though Mr. DiBiagio has taken more gun cases recently, his high-profile endorsement of Exile should result in a powerful team of city, state and federal forces - and he should be applauded for it.
The governor recently filed legislation that would strengthen Maryland's gun laws, and he plans a gun violence summit soon. A number of businesses have agreed to finance a public advertising campaign to let criminals know Exile awaits them.
A coordinated effort has been desperately needed. The murder rates in Baltimore and Prince George's County are far greater than the average rate in other Maryland jurisdictions.
Last year in Baltimore, 367 individuals were arrested for illegal possession of a firearm - an Exile-type offense. For various reasons - including poor police work and weaknesses in Maryland law - only 40 of the 224 persons charged, or less than 20 percent, went to jail.
Overall, the U.S. attorney's power should come as a tonic for hardworking but discouraged police officers and prosecutors in need of some victories over the city's gun-toting thugs.
Mr. DiBiagio's involvement will make a difference. But his decision puts new pressure on Baltimore police, since he's demanding cases that can be successfully prosecuted - a standard that up to now has not always been achieved.
Offenders need to know, surely, that alternatives to crime are available. But until the epidemic of gun crime subsides - until the gun culture changes - punishment must be the priority. And federal punishment is the best deterrent.