Maryland Gov. Martin O'Malley (D) details proposed gun-control legislation this month at the Maryland State House. (John Wagner/The Washington Post)

Maryland Gov. Martin O’Malley’s plan to force residents to submit digital fingerprints, learn how to fire a weapon and pass a series of background checks before purchasing a firearm is most likely constitutional, according to the state’s top law enforcement official.

Attorney General Douglas F. Gansler (D) said Tuesday that he believes the centerpiece of O’Malley’s response to last month’s Newtown shooting would stand up to legal challenges. And he sought to downplay concerns raised by Senate President Thomas V. Mike Miller Jr. (D-Calvert) that if passed, the legislation could “trample on” Second Amendment rights.

“Law-abiding gun owners have nothing to fear,” Gansler said in a news release, taking a pro-forma request to analyze the bill to publicly wade into the state’s gun-control debate.

The opinion, written by Dan Friedman, Gansler’s chief counsel to the General Assembly, said that under a test used by the U.S. Court of Appeals for the Fourth Circuit, O’Malley’s licensing plan would pass a test as “presumptively lawful.”

Friedman acknowledged that under a D.C. Circuit Court ruling, it could be held to a different standard, but said he thought it would pass that bar, too.

The opinion did not, however, address a key question that lawmakers say remains about O’Malley’s plan, which would require new gun purchasers to renew their licenses every five years. If they fail to do so, what happens, lawmakers ask?

Those gun owners would no longer be able to legally possess a firearm, so would they be fined? Imprisoned? Have their weapons seized? Maryland lawmakers say it’s not clear.

O’Malley is scheduled to testify in support of his proposal Feb. 6.