Deputies said they found the victim slumped over in the driver's seat of a car in the 12700 block of Huffmeister Road near Whispering Valley drive around 9:45 p.m. Monday, though he may have been shot somewhere else.
Investigators said a bullet appeared to go through his back and out of his chest.
The victim was taken to the hospital in critical condition. Deputies said he was undergoing surgery.
There was a passenger in the car with the victim, deputies said. He was not injured.
Though it's unclear exactly what led up to the shooting, deputies said they believe it may have been drug-related.