Last week, 37-year-old Ryan Moore was convicted of first-degree murder in what has become known as the "49th Street Massacre."
In 2006, Moore and another man used assault rifles to shoot and kill 10-year-old David Marcial, his uncle, Larry Marcial, and a 17-year-old neighbor.
Prosecutors say Moore was on a gang retaliation mission, but that none of the victims was involved in gangs.
Moore faces sentencing in July.