The boy, a resident of San Joaquin, has been booked into the Fresno County Juvenile Justice Campus, the sheriff's office says.
According to homicide detectives, he shot and killed 19-year-old Yordy Urbieta of Tranquillity on Tuesday at about 8:30 p.m.
The shooting was gang-related and took place in the area of Nevada and 6th Streets.
Another shooting took place at the same location Thursday night, less than 48 hours after Tuesday's shooting.
However, it is not yet clear if the two shootings are related.