Trevon Boswell, 24, was fatally shot in the hallway of his Mount Vernon, New York, apartment building on Washington Street in the early hours of May 22, 2017. He had been returning from a rap showcase in Brooklyn with his brother when the confrontation occurred. His family, who had recently moved into the building, heard the commotion and brought him upstairs while calling for help. Boswell was the father of a young son.

Investigators tied his killing to a violent crime spree across Westchester County and the Bronx that victimized multiple people during a roughly 12-hour period. Within 24 hours police traced a ping from a stolen iPhone and arrested several suspects. Five men — Eric Lee, Sincere Smith, Allen Copeland, John Oquendo and Leroy Garcia — were charged in connection with the spree and Boswell’s death; the group faced counts including murder, robbery and weapons possession. Eric Lee pleaded guilty to first-degree murder and Sincere Smith pleaded guilty to first-degree manslaughter; both received lengthy prison terms, and co-defendants also pleaded or were convicted for roles in the robberies and killings.

Did anyone who knew Trevon in Mount Vernon or attended that Brooklyn showcase see anything that could help fill gaps in the timeline?