A corrections officer caught the two on April 4 in a small prison classroom, with their pants unzipped, KXLY-TV of Spokane (http://bit.ly/14NBC9E ) reported Monday, citing a report from Airway Heights police.
The report said the counselor, whose name has not been released, acknowledged having sex with the inmate. Police want her charged with misconduct. She has resigned from her job.
The report said the counselor concealed her relationship with the inmate by writing him letters under an assumed name and used a bogus return address.
The counselor "had planned to have an affair with (the inmate) after he was released" in October, it said.
Prison officials are treating the case like a sexual assault and view the inmate as a victim.
"Being raped in prison is never to be part of an offender's sentence," said spokeswoman Risa Kleme of the Airway Heights Corrections Center. "We are their custodians and we're here to provide their safety and security while they are incarcerated."