The House of Delegates gave preliminary approval to its version of Gov. Martin O'Malley's gun control bill Tuesday night after defeating scores of amendments that attempted to weaken it.
In a prolonged and heated debate, delegates ultimately preserved provisions to license handgun purchasers, ban the sale of assault-style weapons and limit magazines to 10 bullets. Though the House has modified some provisions of O'Malley's bill, the legislation would still represent the most sweeping change to Maryland gun laws in nearly two decades.
Delegates, primarily Democrats, voted down most of the proposed changes by margins large enough to suggest the bill's supporters have enough votes to pass the legislation. The bill advanced without a roll-call vote.
"This bill is directed to what Maryland needs, and the problem Maryland has is with handguns," said Del. Kathleen Dumais, a Montgomery County Democrat. "The portions of this bill that will make a difference on crime in Maryland are licensure and the assault weapons ban."
Opponents unsuccessfully tried to remove from the banned list the AR-15 rifle that was used in December's Newtown, Conn., shooting of 20 school children and six educators. The nation's second most deadly shooting massacre prompted a wave of federal and state proposals to strengthen gun laws and address mental health services.
Efforts to strip licensing out of the bill and exempt competitive shooters from the assault weapons ban also failed, as well as an effort to delete every portion of the bill that dealt with guns.
"Shame on you for using the blood of children to take away the constitutional rights of the citizens of Maryland," Del. Michael Smigiel, an Eastern Shore Republican, said after several suggestions to weaken the bill failed.
The state Senate in February passed O'Malley's bill with limited changes, but the House is considering a version that would narrow the definition of an assault weapon, ease training requirements for some buyers getting a handgun license and exempt more people from the gun control bill's rules.
The House version also allows assault weapons ordered or in a gun manufacturer's inventory before the ban takes effect to be sold. It would ban certain "cop-killing" bullets, require people to report lost guns to police within 72 hours and bar gun ownership for people sentenced to probation before judgment in violent crimes.
The House is expected to resume debate Wednesday and could take a final vote then.
Unless some of the House additions are changed on the floor, lawmakers said, it is likely the gun bill will head to a conference committee to resolve differences. The session ends Monday.
"If it emerges as it is drafted, it will have work that needs to be done on it," said Sen. Brian Frosh, a Montgomery County Democrat who shepherded the Senate's version through more than 12 hours of debate in his chamber.
Some senators expressed concerns about changes they say might weaken the assault weapons ban by deleting some of the features that define an assault weapon. The law would ban the sale of 45 guns by make and model, along with their "copycats," which are defined by a list of potential gun features such as a grenade launcher and a flash suppressor. The House deleted other features from the list, including a threaded barrel, pistol grips, telescoping stocks and thumb-hole stocks.
The concern is that future models of assault-style weapons might be allowed under the revised language. "The provisions banning copycats in the federal assault weapons ban was critical because it's so simple to make small cosmetic changes and evade the letter of the law," said Sen. Jamie Raskin, a Montgomery County Democrat.
House Republicans and some conservative Democrats planned to offer Tuesday as many as 50 amendments, many of which were rejected in the joint committee vote Friday night that forwarded the bill to the House floor.
"It's two different worlds," said Del. Talmadge Branch of Baltimore, the House majority whip. "In the urban areas, there are no woods, there are no animals. If you're going to have a handgun, it's for protection of your home, protection of your business, or it's for a reason that isn't legal."
Baltimore Sun reporter Michael Dresser contributed to this article.