"We're going to keep the pressure on," the Chelan County Sheriff told USA TODAY June 12 as he prepared to board a helicopter to help in the search.

The girls, Olivia, Evelyn, and Paityn, were found dead near a campground on June 2, three days after they were last seen alive.

Police have narrowed their search for Travis Decker, suspected of murdering his three daughters, to the area of Ingalls Creek and Valley High in Washington state. This case has drawn national attention due to the severity of the allegations,