A Mitchell man who pleaded guilty to first-degree rape of a minor under the age of 13 was sentenced to 90 years in prison on Tuesday. 43-year old Robert Gerstenecker originally faced multiple counts of child pornography. Several other charges were dropped in exchange for the September guilty plea. Under the plea deal, a 75-year prison sentence had been recommended. However, Judge Chris Giles added 15 more years to Gerstenecker’s sentence. A tip from a reporting party who saw what was believed to be child pornography during a video call with Gerstenecker led authorities to obtain a search warrant of Gerstenecker’s residence. Officers allegedly found methamphetamine and a hidden cell phone which contained an SD card with images and videos of child pornography, including some with a man believed to be Gerstenecker engaging in sexual acts with a 7-year old female. The acts are believed to have occurred between October of 2021 and January of this year.