The common thread is unstable Democrats:
[…]Ft Hood: Registered Democrat/Muslim.
Columbine: Too young to vote; both families were registered Democrats and progressive liberals.
Virginia Tech: Wrote hate mail to President Bush and to his staff.
Colorado Theater: Registered Democrat; staff worker on the Obama campaign; Occupy Wall Street participant; progressive liberal.
Connecticut School Shooter: Registered Democrat; hated Christians.
Since liberal progressive Democrats seem to hate guns, and due to their history of mental illness, maybe we should demand a weapons ban to all registered Democrats? After all, 99% of those behind bars vote Democrat because they tend to be liberal with laws. Liberalism is a disease.