Off-duty Walker Police officer shoots man, himself in Chicago
3 dead in Indiana mall shooting and a witness kills gunman, police say : NPR
Authorities still searching for gunman's motive in Allen outlet mall shooting, Allen American
Highland Park parade shooting - Wikipedia
In the Aftermath of a Police Killing, Justifications Start Immediately
At least 8 people killed by gunman at Texas mall; shooter killed by police
Mall of America shooting alleged gunman, accomplice arrested
Lewiston, Maine shooting kills, injures dozens: Police
Multiple mass shootings over Halloween weekend leave 11 dead and scores injured
Texas Mall Shooter Identified, Was Possible Neo-Nazi Sympathizer: Reports