Sentencing will be in a couple of weeks.
Metropoulos had already pleaded guilty to child pornography charges.
The trial began Monday with testimony from a former altar boy at St. George Greek Orthodox Church who said he had been sexually assaulted by Metropoulos when slept at the priest's home as a teenager.
The man, now 23, says he often pretended to be asleep during the assaults.
Metropoulos has been unable to make bail since his arrest in September.