The shooting happened around 1 p.m. at the Friendly Way Convenience Store on Florida Avenue in DeLand, police said.
The suspect, identified as 17-year-old Tyrique L. Matthews, shot the store employee in the leg during the altercation, police said.
The victim was rushed to Central Florida Regional Hospital in Sandford. Police said no further details about the victim were being released.
Matthews is considered armed and dangerous, police said. He may also go by other names including “Trique.”
Authorities asked anyone with information about Matthews’ whereabouts to call the department’s non-emergency dispatch line at 386-943-8276 or call 911 if it is an emergency.