William Sandifer, a 25-year-old African American man, was shot to death on June 14, 2016, in the 14800 block of Turlington Avenue in Harvey, Illinois. He was struck in the back and pronounced dead at Ingalls Memorial Hospital at 10:14 p.m. The Cook County medical examiner confirmed the shooting; initial circumstances were unclear.

Family members say Sandifer attended a gathering that day, left the residence, and was confronted by a masked man who emerged from bushes in the backyard. Investigators report Sandifer and 31-year-old Antowaun Mathis had exchanged words at the gathering and had been in an earlier altercation; police identified Mathis as the primary suspect and say the shooter waited in the yard and shot Sandifer as he followed.

Mathis was arrested by the U.S. Marshals Service in Hampton, Virginia, on August 24, 2016; he was found living in a motel and held in the Hampton City Jail pending extradition to Illinois. The killing was the second homicide in Harvey in 2016. Did anyone at the family gathering or nearby that night see something that could help explain what happened?