Ioannis Kostikidis, 53, was shot and killed as he walked to his car after work.
It happened just before 9:00 p.m. Thursday in the 600 block of North Tatnall Street.
Kostikidis worked as a security guard at the American Beauty Academy.
The owners of the school are offering a $10,000 reward for information leading to the arrest and conviction of the killers.
Witnesses reported seeing two men fleeing south on North Tatnall Street. They are described as black males, wearing black hooded sweatshirts with the hoods pulled over their faces.
Anyone with information is urged to contact Wilmington Police.