PITTSBURGH — Former Pittsburgh Police Chief Nathan Harper has been sentenced to 18 months in prison for conspiring to create an unauthorized slush fund.

U.S. District Judge Cathy Bissoon today also ordered 61-year-old Harper to repay $31,986 from the fund that he spent on himself.

Harper resigned a few weeks before he was indicted on conspiracy charges and failing to file tax returns between 2008 and 2011.

He pleaded guilty in October to conspiracy to commit theft as well as the tax charges.

Defense attorneys argued that his otherwise spotless service record would make probation appropriate.

Federal prosecutors sought a term between 18 and 24 months in prison.