20-year-old Marcus Anderson, of St. Louis, Missouri is described by police as "mentally challenged", althgough they didn't identify specific disabilities. Marcus and his family had just moved into a new home. A person who had lived in the house before, a family friend, had left behind a shotgun that had been spray painted gold. In an effort to hide the gun until she was able to properly dispose of it, Marcus' mother put the shotgun behind a dresser.
Marcus found the gun. He didn't realize it was a real gun and unintentionally shot and killed his 15-year-old sister Alicia.
According to a neighbor, "The little girls was in the shower as she got out of the tub and put on her robe as she was walking out of the door, boom he shot her in the head." She added that after the shooting Marcus kept repeated "I didn't know it was a real gun."
Police arrested Marcus and charged him with 2nd Degree Involuntary Manslaughter.