Authorities warned people to be on the lookout for Decker and asked those with remote homes, cabins or outbuildings to keep them locked, to leave blinds open so law enforcement can see inside and to leave exterior lights on.
It was unclear if Decker was armed, but the Chelan County Sheriff's Office said he should be considered dangerous. A reward of up to $20,000 was offered for information leading to his arrest.
An online fundraiser for Whitney Decker raised more than $1 million, and friends Amy Edwards, who taught the girls in a theater program called “Short Shakespeareans,” and Mark Belton thanked supporters during a news conference Thursday.
“Their laughter, curiosity and spirit left a mark on all of us,” Edwards said. “They were the kind of children that everyone rooted for, looked forward to seeing and held close in their hearts.”