The Skagit Valley Herald reported police are treating the shooting as a homicide.
Police believe 25-year-old Trevor Braymiller is armed and dangerous. Braymiller is a convicted felon and is not allowed to have firearms.
Police first responded to calls of a child shot early Sunday.
Lt. Lin Tucker said Braymiller was a father figure to the child, although not his biological father.
The boy was taken to Skagit Valley Hospital but was pronounced dead there.
Tucker said the house where shooting occurred is well known to authorities. In 2011, police conducted a drug raid there. They have also seized firearms from Braymiller before.
Information from: Skagit Valley Herald, http://www.skagitvalleyherald.com
More Northwest Headlines
Winds shifted minutes before firefighters killed, documents say 7:57 a.m. Crews encounter smoky conditions battling E. Wash. wildfires College students dive in to marine life at Rosario Beach Army appeals court reverses JBLM soldier’s rape conviction 'Cougar nation' remembers WSU President Elson Floyd Insurance companies sue over Seattle tunnel machine repair Seward Park swimming beach on Lake Washington closed after sewage spill Search for diver missing near Cape Flattery suspended
Our new comment system is not supported in IE 7. Please upgrade your browser here.