Natalie Rupnow, who killed two during a school shooting, was pictured in the shirt at a gun range before the attack. Newsweek ...

Merchandise relating to UnitedHealthcare CEO Brian Thompson's killing in New York City quickly appeared online following the shooting.

The 15-year-old girl who carried out a deadly school shooting in Madison, Wisconsin on Monday photographed herself wearing the same t-shirt as one of the infamous Columbine High School gunmen.