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
Roseburg sheriff says college gunman committed suicide 2:23 p.m. Shooterís dad says he had no idea his son had guns 3:15 p.m. Drought destroys Whidbey Island farmerís pumpkin patch 2:23 p.m. Man accused of assaulting victim, stealing his pants 12:47 p.m. Pasco Police: Teen shot while trying to steal pot plants 12:46 p.m. Survivor: Roseburg gunman spared student to take package to police Survivor: Gunman spared student to take package to police Veteran who tried to stop Oregon gunman was shot 5 times
Our new comment system is not supported in IE 7. Please upgrade your browser here.