A judge on Thursday ordered a registered sex offender to prison for a repeat offense involving an underage girl.

Douglas County District Judge Mike Malone ordered 36-year-old Nick F. Mathis, formerly of Baldwin, to serve a total of nearly three years. Mathis was convicted of having inappropriate sexual contact with a 15-year-old acquaintance last year while he was on probation for a previous incident involving a 9-year-old Eudora girl.

The judge revoked Mathis’ probation for the earlier crime and ordered him to spend about 28 months in prison for that offense. In the second case, Malone sentenced Mathis to a year in jail for one count of sexual battery, but Mathis received credit for about eight months he’s already spent in jail.

Prosecutors didn’t oppose Mathis’ request to serve the jail sentence and prison sentence at the same time, but Malone strung them back-to-back at the request of the victim’s mother.