By Steve Tawa and Pat Ciarrocchi

PHILADELPHIA (CBS) — One of the main figures in the Philadelphia clergy child abuse trial has taken the witness stand to point a finger of  blame at Father James Brennan, who is charged with attempted rape.

The accuser, now 30 years old, took the stand confidently, but by the time he recounted his overnight visit to Father Brennan’s apartment in West Chester in 1996, when he was just 14, he was trembling and sobbing.

He says Brennan showed him pornographic chat rooms on the computer and talked explicitly about male body parts.  Then, Brennan insisted they both sleep in one bed. That’s when, the accuser says, the priest sexually assaulted him.

The man said he went from a being straight ‘A’ student to a downward spiral of drugs, alcohol, and crime.  He attempted suicide three times.

He says he last saw Father Brennan in 1999, while he was doing community service at age 17 for several crimes, including forgery, ID theft, and making a false report to police.  As he fetched tools while doing landscaping work on church grounds at Assumption BVM in Feasterville, he caught Brennan in a shed with his pants down.  He says he walked away when Brennan invited him in.

The defense used cross-examination to attack the credibility of the priest’s troubled accuser.

Brennan, who is charged with attempted rape, has denied any wrongdoing (see previous story).