The boy has been charged with murder and is in custody at the Juvenile Justice Campus.
The deadly shooting happened at Motel 6 Blackstone South in central Fresno on August 24. The victim, 24-year-old Philip Frusetta, was found by officers lying dead on the second-story landing of the motel, having been shot once in the chest.
Fresno police on Monday described the shooting as a 'senseless act of violence'.
Fresno police say earlier in the night, there was a disturbance between some boys and girls in the motel, and Frusetta had asked them to leave the property.
In 2019, Action News interviewed Frusetta and his then-2-year-old son Masen, shortly after the young boy's mother, Mina Serrano, was killed in a crash.