No surprise. From TH Online:

A federal judge on Tuesday upheld a Maryland ban on 45 assault weapons and a limit on gun magazines to 10 rounds, two key parts of a sweeping gun-control law that were challenged shortly before the law went into effect last year.

[ . . . ]

U.S. District Judge Catherine Blake concluded in a 47-page ruling that the law serves the government’s interest in protecting public safety without significantly burdening what the Supreme Court has explained is the core Second Amendment right of “law abiding, responsible citizens to use arms in defense of hearth and home.”

“In summary, the Firearms Safety Act of 2013, which represents the considered judgment of this state’s legislature and its governor, seeks to address a serious risk of harm to law enforcement officers and the public from the greater power to injure and kill presented by assault weapons and large capacity magazines,” Blake wrote in her ruling.

In other words, just the act of owning an AR-15 turns a person into a killer.