Officers responded to The Landing at Francher Creek apartments on Clay and Peach Avenues on Thursday morning.
Investigators say the suspect got into a fight with his mother's 52-year-old boyfriend and shot him in the stomach.
The victim was taken to hospital and is expected to survive.
The 19-year-old suspect ran from the scene after the shooting. Officers tracked him down to an area near a canal south of McKinley Avenue near Chestnut.
He was hiding in some bushes and eventually surrendered to the police.
Officials say the elementary school across from the apartment complex was not affected by the investigation.
EDITOR'S NOTE: Initial information from Fresno police said the suspect was the victim's son. Our story now reflects the updated information from authorities.