As the search for Travis Decker continues, more details are coming to light about the former military man’s declining mental health before his three daughters were found dead.

Authorities believe they have tracked Travis Decker, an ex-soldier wanted in the death of his three young daughters, to Blewett Pass, an isolated stretch of the Cascades in central Washington.

Here's what to know about Travis Decker, suspected of killing his daughters Paityn, Evelyn and Olivia in Washington state.