Sheldon Williams was 20 and a resident of Southeast Washington, D.C., when he was found dead on a paved trail in the Briggs Chaney area of Silver Spring, Maryland, on March 11, 2016. His cause of death was a gunshot wound to the back of the head, and Montgomery County Police opened a homicide investigation after his body was discovered late that night.

Detectives say Williams went to an apartment on Castle Boulevard intending to buy marijuana. Investigators identified 27-year-old Mouctar Sylla of Silver Spring as the suspect and arrested him on a charge of second-degree murder. Police reported finding items in Sylla’s apartment consistent with drug distribution — a digital scale, plastic bags, marijuana packaged for sale, and more than $11,000 in cash, some hidden in a toilet tank. Sylla was also charged with use of a firearm in the commission of a murder, illegal possession of a firearm by a person previously convicted of a violent crime, and possession with intent to distribute.

Does anyone have information about Williams’s movements in Silver Spring on March 11, 2016, or about the Castle Boulevard apartment?