LITTLETON, Colorado — Teenage gunmen spilled the blood of children before Columbine — in Alaska, Arkansas, Mississippi and Oregon. After Columbine, more blood was shed in Minnesota and California, in Germany and Finland. But none of those tragedies cast a shadow as long or dark as the rampage at Columbine High School, where 13 people were gunned down 10 years ago Monday. Eric Harris and Dylan Klebold, seniors at the suburban Denver school, detonated homemade bombs... (GunPolicy.org)