Police arrested 53-year-old David Scratchley in September 2011 at his Belltown apartment building, where they also found the boy.
Scratchley, a former counselor at the Matt Talbot Center, is alleged to have told a patient at the center that he planned to have sex with the boy. The woman told police, who arrested Scratchley and found the boy at the counselor's apartment.
The arrest follows a long career in which Scratchley built a solid reputation for treating children and adults with addictive behaviors. An online biography credits him with treating thousands of people for drug addiction.
Most recently he has served as clinical director of the Matt Talbot Center in Seattle, a treatment center providing drug and alcohol and mental health services to individuals with severe addiction.
Scratchley also has served as an instructor at Seattle University and was formerly a director at Seattle Children's Home, a leading psychiatric facility, where he oversaw several programs. He also lectures on the national circuit.
Scratchley faces a sentence of 56 months in prison. The charge also carries an indeterminate maximum sentence of up to life in prison, according to prosecutors. A sentence would also require lifetime sex offender registration and community supervision if he's released.
Sentencing is set for May 3.