Puffinburger was taken from his home, when police said two men entered the house and tied up the boy's mother and her boyfriend. The house was ransacked and the boy was taken.
The abduction triggered a nation-wide Amber-Alert. The alert was called of Saturday following the arrest of the boy's grandfather, Clemens Tinnemeyer in Riverside.
Police believe the kidnappers were Mexican drug dealers and the kidnapping was meant to send a message to Tinnemeyer.
Tinnemeyer may have stolen millions of dollars from the Mexican dealers, said Officer Cris Johnson, a Las Vegas police spokesman.