MENDOZA, Argentina (AP) — Downcast and sitting in a wheelchair as his historic trial began Monday in Argentina, the Rev. Nicola Corradi didn’t look like the man former students at an institute for the deaf say was the force behind years of “indescribable” torment through alleged sexual abuse.

The 83-year-old Italian priest, along with the Rev. Horacio Corbacho, 59, and Armando Gómez, 63, are being tried for 28 cases of alleged abuse against ex-students at the Antonio Próvolo Institute for Deaf and Hearing Impaired Children in Mendoza province. They face prison sentences of up to 20 years in some cases, up to 50 years in others.

The alleged abuse took place between 2004 and 2016, and the case gained world attention when it emerged that Corradi had faced similar accusations at the Antonio Próvolo institute in Verona, Italy, and Pope Francis had been notified the Italian priest was running a similar center in Argentina.