Wednesday is a crucial day for gun control advocates in Maryland, where the House of Delegates is set to vote on Gov. Martin O'Malley's sweeping gun-control bill.
The bill would ban assault weapons, limit magazines to 10 bullets, and require gun buyers to submit their fingerprints to the state.
Democratic lawmakers defeated Republican efforts to weaken the measure Tuesday night.
The House has made some changes to the bill approved by the Senate more than a month ago: Two committees amended the governor's bill to cut down on the list of rifles that would be banned. However, the strongest parts of the bill remain.
O'Malley, a Democrat, proposed the measure in the aftermath of December's massacre at a Newtown, Conn., school, where a gunman killed 20 children and six adults before committing suicide.