Seung Hui Cho slipped through a loophole in Virginia law when he bought his gun. Lawmakers in that state fixed the problem
The deadly mass shooting in Tucson on Saturday was by no means the first to raise questions about how mentally ill people bought firearms.
In some cases, state or federa ... More >>
Saturday's shooting rampage in Tucson, which left six people dead and 14 others injured -- including Congresswoman Gabrielle Giffords -- is just the latest in at least 30 documented rampage shootings in American history.Listed below are 10 of the deadliest: