People were asked to avoid the area to allow officers to conduct the investigation.
Prince George's County police identified the woman who died as Daijah Cherry, 18, of Washington, D.C.
Police said the three incidents are not related.
The violence follows multiple Saturday morning shootings and a stabbing that took place in the District.
MPD said investigators were looking for a man with a full beard, wearing dark clothing and driving a dark-colored sedan with ...