Abdullah Trull, 16, was one of three people killed in a mass shooting on October 9, 2013, in the South Shore neighborhood of Chicago. Multiple gunmen approached a group standing in a courtyard at the 6700 block of South Chappel Avenue and opened fire. Abdullah was with his twin brother, who witnessed the shooting.

Reports tie the attack to a confrontation that began when occupants of a red car asked about buying marijuana; that encounter escalated into gunfire and multiple fatalities. Abdullah’s death was one of several in a pattern of deadly shootings in the city that have affected young people and their families.

If anyone witnessed the shooting or knew Abdullah and his twin brother, please share what you know with investigators.