PITTSBURGH — Former Pittsburgh Police Chief Nate Harper has entered a minimum security prison in Illinois to begin serving time for a corruption conviction.

A prison spokesman says that Harper entered the camp in Pekin, Illinois, at about noon Tuesday.

Harper pleaded guilty to charges of failing to file income tax returns and corruption in October 2013. He joined the city’s police force in 1977 and rose through its ranks to become chief in 2006. The corruption charge was for Harper’s role in a scheme that diverted more than $70,000 from a city account.

On Monday, Harper’s attorney appealed a ruling that stripped him of a $63,000 yearly pension. Attorney Samuel C. Stretton argues that none of the crimes Harper was convicted of are listed as grounds for forfeiture.