He was convicted of killing his mother 15 years ago, Earlier this month he 'walked' away from his psychiatric facility in Pendleton.

Thursday, Oregon officials with the Psychiatric Security Review Board posted notice they are seeking assistance in locating 36-year-old Thaddeus Ziemlak. He was last seen January 5 when he was leaving the residential facility for a planned outing, but never returned.

He was said to be stable at the time of his disappearance, but officials say his history of drug abuse can cause irrational and dangerous behavior. Anyone who sees him is urged  to NOT approach him and to call 911.

In February 2004 his mother was found dead having been shot twice in the head, Thaddeus was found not guilty by reason of insanity. He's previously tried to escape custody back in 2006, but was located in Wenatchee.

Authorities have not said why they waited nearly 3 weeks before issuing the missing notification.