Defense lawyers questioning the gaunt, 24-year-old policeman's son poked several holes in his accounts, some of which he attributed to years of heavy drug use.
The man said he as "semi-comatose ... but standing" when he first spoke with a church investigator in 2009.
The witness, with prompting from a counselor, had called the archdiocese from a drug clinic, ultimately reporting that two Roman Catholic priests and ex-teacher Bernard Shero had sexually assaulted him in about 1999.
Shero, 49, of Levittown, and the Rev. Charles Engelhardt, 66, of Wyndmoor, are on trial, fighting the charges. Now-defrocked priest Edward Avery is in prison after pleading guilty.
During cross-examination Wednesday, Shero's lawyer said the accuser has said over the years that the teacher raped him in his sixth-grade classroom, near a trash bin outside an apartment complex and in the parking lot of a city park.
The accuser explained that he was high when he spoke to the church investigator in a car outside his parents' house, and doesn't remember much of the conversation. His drug habit at times reached 15 to 20 bags of heroin a day, the young man acknowledged.
"You have a very clear memory of what happened when you were 10 years old, but you don't remember what happened in the car in 2009?" asked Engelhardt's lawyer, Michael McGovern.
The abuse allegedly started with Engelhardt in fifth grade, and continued that year with Avery. Avery raped him in the sacristy after Mass when he was a 10-year-old member of the church's bell-maintenance crew, the witness said.
But under cross-examination, McGovern said the school only allowed eighth-grade boys to join the bell crew. The witness said that surprised him.
The man's complaint led to last year's landmark child-endangerment conviction of the Rev. William Lynn, who oversaw priest assignments at the Archdiocese of Philadelphia from 1992 to 2004. Lynn acknowledged that he sent Avery to St. Jerome's Parish in northeast Philadelphia even though Avery had admitted to an earlier abuse complaint. Lynn, 62, is serving a three- to six-year prison term for felony child endangerment.
Avery, serving 2 1/2 to five years, is expected to testify for the prosecution Thursday. He would be the first admitted priest-pedophile to testify in open court during the 11-year investigation of church abuse within the Philadelphia archdiocese.
The accuser also has sued the archdiocese. Observers watching the trial this week include his civil lawyer, a juror from the Lynn trial and the father of a young man who committed suicide after filing a priest-abuse lawsuit against the church.
The accuser was asked Wednesday how much money he hopes to win.
"No money would make this better. I'm not doing this for a dollar," he said. "They told me ... it would put a stop to it."
Defense lawyers attacked other details from his statements, such as one account in which he said he was raped at church for hours without anyone finding them.
They also elicited emotional comments about the death of his grandmother, whom he described as a second mother. She died of cancer when he was in ninth grade—weeks before he was first arrested and expelled from school for having drugs and brass knuckles, they pointed out.
After the grandmother died, he secretly got a tattoo on his back to honor her. It features a large cross and says, "In Memory of Maggie."
The accuser's father, now a police sergeant, also testified. He poignantly described the trauma the family experienced as his once-joyful, extroverted son descended into heavy drug use and suicidal behavior—and refused to tell them what was wrong.
"That was my biggest fear, that I was going to find him dead," the sergeant said.