It happened in the Walmart parking lot in the 9700 block of Roosevelt Blvd. around 9:30 p.m. Thursday.
Police say two drivers argued over being parked too close to each other.
An 18-year-old female inside a pickup truck was shot in the shoulder, while the 50-year-old driver had a graze wound to the head.
Three juveniles in the truck were not hurt.
There has been no word on any charges.