It happened around 9 p.m. along the 4000 block of City Avenue.
Police said 25-year-old Daykwan Carter was found in a Jeep Grand Cherokee with an apparent gunshot wound to the head. He was pronounced dead at the scene.
The Jeep with a bullet hole in the passenger side window remained in the parking lot for hours after the shooting as police investigated.
Two other male victims, a 31-year-old and 24-year-old, ran into the store looking for help, police said.
They were taken to Lankenau Hospital with gunshot wounds to the back and shoulder; they are listed in critical condition.
Authorities are looking into whether the two men were in another Jeep that crashed into several parked cars in the parking lot.
"It's absolutely dangerous. The fact that there weren't more people who were injured-- you know we're very, very fortunate," said Acting Police Commissioner Christine Coulter. "The fact that someone would either want something bad enough or want to protect something bad enough to open fire in a parking lot is absolutely frightening."
Two guns and what appeared to be a bag of marijuana were recovered at the scene, according to authorities.
Coulter said the shooting may have been either an attempted robbery or a drug deal gone bad.
She said officers were already at the Target investigating an unrelated incident when the shots rang out.
Early Wednesday morning, people were allowed to get to their cars that were behind the crime scene tape as police conducted their investigation.
No arrests have been made. Police said they are looking for a possible fourth person connected with the shooting who got away.
Anyone with any information is asked to call police at 215-686-TIPS.