What was Orestes' 'alleged' crime?

Answer 1

The murder of his mother committed to avenge the murder of his father committed to avenge the sacrifice of his sister committed to appease the gods and blow the Greeks to Troy to avenge the theft of Helen of Sparta to spite Athena and Hera to win a golden apple because Eris wasn't invited to a wedding held to nullify a prophecy that the son of Thetis would surpass his father and Zeus knew he'd eventually father her son so he married her to a mortal so that only an exceptional demigod would be produced. His name was Achilles.