Sasso began his priesthood in the San Juan archdiocese, where he was diagnosed in the early 1990s as a pedophile. He was sent in 1996 or 1997 to Domus Mariae, a Catholic church-run treatment center for priests with pedophilia and other disorders in the diocese of Zárate-Campana , in the city of Tortuguitas, Buenos Aires province (25 miles northwest of the city of Buenos Aires).
Sasso left the center in 1998 with instructions never to be in the company of children.
In 2001, the Zárate-Campana bishop, Rafael Rey, assigned him to work at San Miguel de La Lonja, an impoverished parish in the city of Pilar, where Sasso was the sole priest and in charge of a community soup kitchen. There he sexually assaulted at least five girls, ages 5 to 12, all from extremely poor families. He would lure the girls into his bedroom with offers of candy and television, and then undress them, grope them, and masturbate in front of them. He threatened the girls to ensure their silence.
In 2003, a 12-year-old girl who frequented the soup kitchen ("dining hall") for meals confided her abuse to Lia López, a woman who worked there. López immediately contacted the diocesan vicar for Pilar, José Ramón de la Villa, who reportedly told Bishop Rey. When neither church official acted to remove Sasso, López and a priest-psychiatrist named Luiz Guzmán went to law enforcement, which on 12/1/2003 issued an order for Sasso's arrest.
Sasso fled the country, abetted by Rev. de la Villa and his secretary Rev. Gabriel Michelli. Sasso hid for a short while in Paraguay. He was captured in January 2004, when he tried to re-enter Pilar in order to renew his passport so that he could travel overseas. In February 2004, Revs. de la Villa and Michelli were charged with aggravated concealment; they eventually admitted partial guilt and were given probation. Bishop Rey was not charged but reportedly was forced by the Vatican to resign early, at age 72 (mandatory retirement age is 75).
In 2006, as Sasso's case languished and more victims came forward, the families of the young girls requested a meeting with Cardinal Bergoglio of Buenos Aires, who recently had become president of the Argentine bishop's conference. They received no response.
Sasso was convicted in 2007 of first-degree sexual abuse of minors and was sentenced to 17 years in prison. While in prison, he got married, apparently after being granted voluntary laicization. In 2012, he was allowed a one-day furlough every month.
• De la capilla a un calabozo, by Mariana Carbajal, Página/12, 12.02.2003
• Priest Accused of Sex Abuse Is Detained: The Victim Would Have Been a 12-Year-Old Girl, Clarín, 1.21.2004 [Translation]; en Español
• Investigan a dos sacerdotes por encubrir los abusos de Napoleón, Página/12, 2.09.2004
• The House of the Fathers “In Crisis”, by Miguel Jorquera, Página/12, 9.05.2005 [Translation]; en Español
• La probation que cayó del cielo, by Horacio Cecchi, Página/12, 10.26.2007
• Priest Who Violated Five Girls Is Sentenced to 17 Years in Prison: The Victims Are Between 5 and 12 Years Old, by Georgina Elustondo, Clarín, 11.13.2007 [Translation]; en Español
• Point of View: Measures that Come Too Late, by Lucas Guagnini, Clarín, 11.13.2007 [Translation]; en Español
• Pedophile Priest: Church Assures that It Already Removed a Bishop -- Repercussions from Mario Sasso’s 17-Year Prison Sentence, by Sergio Rubín, Clarín, 11.14.2007 [Translation]; en Español
• Former Pastor Deceased: A Priest with a Controversial and Polemical Image, Pilar de Todos, 2.29.2012 [Translation]; en Español
• El cura que no encontró una cura, by Michel Zeghaib, Tiempo de San Juan, 10.13.2012
• Ex-Priest, Sentenced for Pedophilia, Is Given Transitory Release, Clarín, 11.06.2012 [Translation]; en Español
• Transitory Release Given to Ex-Priest Who Abused Five Girls, Clarín, 11.07.2012 [Translation]; en Español
• Pope Francis Was Often Quiet on Argentine Sex Abuse Cases As Archbishop, by Nick Miroff, Washington Post, 3.18.2013
• Abuse Victims Want Pope to Open Argentina Files, by Michael Warren, WHBF, 3.19.2013
• Hard Questions about Francis in Argentina and a Lesson from Chile, by John L. Allen, National Catholic Reporter, 4.12.2013
• Uno por uno, los 9 curas que ya fueron condenados por abusar de menores en Argentina, Clarín, 9.6.2017
• El protegido: La historia del sacerdote sanjuanino Napoleón Sasso, Diario La Ventana, 7.18.2015