THE GUN LOBBY and its acolytes in Annapolis are mounting an all-out assault to subvert Gov. Martin O’Malley’s bill to establish what would be among the nation’s most stringent gun-licensing regimens. They are taking special aim at the core of the governor’s program: a requirement that gun buyers submit not only to background checks, as they already do, but also to digital fingerprinting by the state police.

The logic of fingerprinting handgun buyers — the bill exempts purchasers of hunting rifles and shotguns, mainly used by sportsmen — is overwhelming. Criminals in need of handguns frequently procure them through friends or other straw buyers. Those straw buyers might not be discouraged by existing background checks, or they might circumvent them by giving a fake name. Fingerprinting is a more muscular deterrent that would all but eliminate the use of false identities.

A number of states, including New York and New Jersey, require fingerprinting for gun buyers; the legislation in most states has been followed by a reduction in firearm crimes. True, Maryland criminals might still buy guns in neighboring Virginia, where the gun lobby’s sway is stronger and gun laws weaker. But that is no reason for lawmakers in Annapolis to do nothing.

Opponents of the legislation contend that fingerprinting is burdensome. Nonsense. Hundreds of thousands of Marylanders in several dozen occupations are already required by law to submit to fingerprinting. They include locksmiths; nursing assistants; jockeys; mortgage originators; teachers; casino workers; and, in Calvert County, palm readers. Does the state have a lesser interest in verifying the identity of gun buyers?

In a debate on the state Senate floor Tuesday, the legislation’s opponents often seemed to grasp at straws. Why, asked Sen. Allan H. Kittleman, a Howard County Republican, do some Democrats want to toughen ID requirements for gun buyers but ease them for voters at the polls? Sen. Brian Frosh, a Montgomery County Democrat who is the bill’s chief sponsor in the Senate, replied succinctly: When voters pull the lever at the ballot box, he said, there’s no one on the other side who might be killed.

The Maryland legislation would be beneficial in a number of ways. It would ban assault weapons; tighten security at schools; impose tougher restrictions on mental health patients who would attempt to purchase weapons; and give state police new tools to crack down on rogue gun dealers.

But the measure’s core is the fingerprinting provision. Removing it would hand a victory not just to the gun lobby but also to criminals and their gun-buying accomplices. That must not be allowed to happen.