The victim killed has been identified as 21-year-old Jah'Mir Johnson, according to police.
It happened around 6:44 p.m. Thursday on the 800 block of East 22nd Street.
Police say Johnson was rushed to the hospital after being shot. He later succumbed to his injuries.
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The shooting also injured a 19-year-old woman and a 9-year-old girl. Both victims are hospitalized in stable condition.
The circumstances surrounding the shooting have not been released.
Anyone with information about this incident is asked to call Detective Joseph Wicks at (302) 576-3654. You can also provide information to Delaware Crime Stoppers at 1-800-TIP-3333 or delawarecrimestoppers.org.