Investigators say the suspect was seen lurking near a liquor store on South Long Beach Avenue near Martin Luther King Jr. Boulevard.
Surveillance tape shows the suspect attacking the victim from behind after he left the store and grabbing his necklace. The victim struggled with the suspect, trying to hold on to his necklace but the suspect managed to run away with it.
He was last seen on Vernon Avenue.
The victim sustained minor injuries.
The suspect is described as African American, 17 to 25 years old, 5 feet 9 inches to 5 feet 10 inches and weighing about 160 to 170 pounds. He was last seen wearing a burgundy, hooded jacket with dark lining and with white letters across the chest, jeans and white tennis shoes.
Detectives believe that he may be responsible for several other robberies in the area.