It happened around 8:45 p.m. Thursday near the intersection of Elm and South Harrison streets.
Authorities say arriving officers found 39-year-old Theodore Jackson unresponsive in the street having suffered multiple gunshot wounds to the torso.
According to police, as officers administered first aid and CPR, crowd of approximately 200 people formed. The group was allegedly hostile, throwing rocks at the officers.
Police called in backup to provide security for arriving EMS personnel.
The victim was transported to Christiana Hospital where he was pronounced dead.
No word a motive or on any suspects.