Spokane, Wash. ? A criminally insane killer who escaped during a mental hospital field trip to a county fair remained on the run Friday, and furious residents and officials wondered why such a dangerous person was out in public.

Authorities believe Phillip Arnold Paul, 47, is heading to the Sunnyside, Wash., area, where his parents and many siblings live. The Spokane County Sheriff’s Office used a helicopter to search Friday, and officers also searched transient camps along railroad tracks in the area. The public was urged to call 911.

“He is in a bad mental state,” his brother, Tom Paul, told The Associated Press. “Why would they load him on a bus and take him to a fair?”

That’s a question many are asking.

Authorities at Eastern State Hospital are being criticized for allowing Paul to visit the fair despite his violent criminal past and history of trying to escape. Spokane County Commissioner Mark Richard has called it unacceptable, and the state Department of Social and Health Services ordered an immediate end to such trips and launched an investigation into the practice.

Paul was committed after he was acquitted by reason of insanity in the 1987 slaying of an elderly woman in Sunnyside. He soaked the woman’s body in gasoline to throw off search dogs and buried the remains in her flower garden.

“Why was he allowed to take such a trip?” Gov. Chris Gregoire said Friday. “Why did they go to a location that was so heavily populated with families?”

Susan Dreyfus, secretary of the Department of Social and Health Services, said those questions would be answered in an investigation she has ordered that included both state mental hospitals.

Dreyfus said it is not unusual for so-called “forensic” patients, who are being held against their will, to earn the opportunity to go on field trips as part of their therapy. The mental hospitals also treat people who are mentally ill but have not committed crimes.