Monsignor William Lynn is the first U.S. church official convicted of a crime for how he handled sex-abuse accusations.
Lynn is on leave from the Philadelphia archdiocese, where he served as secretary for clergy from 1992 to 2004.
Defense lawyers said Lynn alone tried to document abuse complaints, get priests into treatment and alert the cardinal to the growing crisis. Church documents show therapists had called one accused priest a ticking "time bomb" and "powder keg."
Evidence showed a pattern
Lynn testified that the cardinal was the ultimate authority on what happened to the priests.
Prosecutors argued that Lynn could have called police or quit the job if efforts to help victims were being stymied.
They said the evidence showed a pattern at the archdiocese of lying about why priests were removed, sending them to "company doctors" at church-run therapy centers and failing to warn new parishes where they were later transferred.
Friday was the 13th day of deliberations in the case.
Seven men and five women sat on the jury, along with eight alternates. Many have ties to Catholic schools or parishes, but said they could judge the case fairly. There are about 1.5 million Catholics in the five-county archdiocese.