Durham, N.C. — A former Duke University employee should serve "a substantial period of incarceration" followed by a lifetime of supervision for sex crimes against a child, according to sentencing guidelines for the crime filed last week in district court.

Frank M. Lombard, 43, was sentenced Monday to 27 years in prison. He pleaded guilty in December to a federal child sex charge. He was arrested in June after authorities said Washington police caught him in a sting operation.

Lombard was charged with attempting to induce someone to cross state lines to engage in a sexual offense. He pleaded to sexual exploitation of a minor, a charge which carries a maximum sentence of 30 years in prison.

In recommending the sentence, U.S. Attorney Ronald C. Machen Jr. wrote, "The defendant betrayed the trust of his adopted child in the most deplorable way imaginable. His child became nothing more than a pawn in his persistent attempts to gratify himself by sexually molesting him and chatting online with as many other pedophiles as possible."

Lombard was fired from his position as associate director of the Center for Health Policy at Duke in July and has been in a D.C. jail since August.

In court documents, an undercover member of the Washington Metropolitan Police Department described an online chat in which someone named "F.L." invited him to Durham to have sexual contact with his adopted 5-year-old son.

The officer made contact with "F.L" after an informant told FBI agents that he saw a man called “cooper2” perform sex acts on a young African-American child via online chats on multiple occasions. The informant's description of "cooper2" corresponded with the description of Lombard.