According to news reports regarding the Tucson shootings, the suspect, Jared Loughner, used a Glock 19 9mm, a semiautomatic pistol, bought by him about a month prior to the shooting after he passed a federally required background check. Mr. Loughner is reported to have been kicked out of community college recently and to have been perceived as a danger to fellow students and the school. His former math teacher, Ben McGahee, is quoted as saying, "I was getting concerned about the safety of the students and the school. I was afraid he was going to pull out a weapon".
The federal law banning the transfer or possession of semi-automatic assault weapons expired in 2004. Six states ban assault weapons and large capacity ammunition magazines: California, Hawaii, Maryland, Massachusetts, New Jersey and New York.