AVIANO AIR BASE, Italy -- A former Aviano-based airman is serving a 25-year sentence for viewing, possessing and producing child pornography after more than 70,000 digital images and videos were found in his home in Italy. Christopher W. Cluff, a former master sergeant who was reduced in rank to E-1 as part of his sentence and given a bad-conduct discharge, pleaded guilty to four specifications of viewing and possessing child pornography in a February court-martial. He pleaded not guilty to one specification of producing child pornography, but the military judge, Col. Shelly Schools, found him guilty on all charges. He also had to forfeit all pay and allowances. He is serving his sentence in Leavenworth, Kan. “This is the worst child pornography case I have ever encountered,” James Parsons, a defense computer forensic laboratory examiner, said in an Air Force news release. Capt. Brian Hanley, one of the prosecutors, said Wednesday that the conviction came as a result of “hundreds of hours” of work by members of the 31st Fighter Wing’s legal team and contributions from various American and Italian agencies. Cluff’s case started with a tip from the FBI and Europol to the Italian postal police that pointed to an IP address in Italy associated with child pornography. Italian authorities matched the address to Cluff’s home in Sacile, searched the residence and arrested him on April 16, 2015. The U.S. requested and was granted jurisdiction on July 15. Cluff spent most of his time until the court-martial at the U.S. military’s holding facility in Sembach, Germany. Among the more than 70,000 digital images and videos discovered in Cluff’s home were stored videos that came from chat rooms or other online sites featuring minors engaged in “sexually explicit conduct” Cluff was found to have fostered. There was no evidence introduced that he was physically present at locations where the acts took place or that he had engaged in similar activity before he arrived at Aviano. The charges date back to Cluff’s arrival in Italy in December 2013. During the trial, prosecutors offered 3,781 images and 138 video files of child pornography for the military judge’s consideration, according to the release.