OLYMPIA, Wash. (AP) - Authorities have been investigating the disappearance of Susan Powell as a likely murder case, while they publicly left open the possibility that the Utah mother might be found alive.

A Washington state search warrant obtained by The Associated Press through a public records request Tuesday shows that police were investigating three felonies in Utah: first-degree murder, kidnapping and obstructing a public servant.

Salt Lake County District Attorney Sim Gill acknowledged for first time that they believe Powell is likely dead. He says in an AP interview that while the case points to her demise, it remains a missing persons probe for now.

Investigators are reassessing the case after her husband and "person of interest" in her disappearance, Josh Powell, torched his home this weekend, killing himself and their two children.