The 24-year-old policeman's son could be vulnerable on the stand. He has a history of heroin addiction, and has told varying stories about the abuse over the years.
He now says he was high when he gave an early statement to an investigator from the Roman Catholic Archdiocese of Philadelphia.
Lawyers for the Rev. Charles Engelhardt and ex-teacher Bernard Shero are set to cross-examine him Wednesday morning. The men are charged with sexually assaulting the accuser starting at age 10 in 1999.
Another priest from St. Jerome's Parish in northeast Philadelphia has pleaded guilty and is expected to testify for the prosecution this week.