On the morning of October 27, 2017, 31-year-old William Earl Cooper Jr. was found lying on the sidewalk in the 300 block of South Marshall Street in Lancaster, Pennsylvania, with multiple gunshot wounds. He was taken to Lancaster General Hospital and pronounced dead around 8:00 a.m.; an autopsy confirmed the cause of death as multiple gunshot wounds and the case was ruled a homicide.

Detectives identified 41-year-old Wilberto Melendez as the primary suspect after witnesses said Cooper, Melendez, and another man had met on South Marshall Street to resolve an ongoing dispute. According to witness accounts, Melendez allegedly retrieved an item from a Cadillac SRX stopped in the street and opened fire, striking Cooper four times in the chest and abdomen while the other man was not injured. Melendez then reportedly returned to the vehicle, which fled the scene.

An arrest warrant was issued and investigators say Melendez contacted a witness multiple times after the shooting, allegedly instructing them to lie. In February 2018 Melendez was taken into custody during a traffic stop in York County and charged with homicide, witness intimidation, and firearms offenses.