Case Description: Complainant (Clytemnestra) accuses Defendant (Agamemnon) of murder. Just before the Greeks were about to set sail from Aulis, Agamemnon shot a sacred deer of Artemis and/or bragged that he was a better hunter than the goddess. To punish him, Artemis sent a plague among the army and stopped the wind from blowing. It was decreed that the only way Artemis would allow the Greeks to set sail was if Agamemnon sacrificed his daughter, Iphigenia. After a lot of hemming and hawing, Agamemnon went through with the sacrifice, which made his wife Clytemnestra pretty unhappy.
Case Status: Case closed. When Agamemnon returned from the war, Clytemnestra got her revenge by stabbing him to death in a bathtub and marrying his cousin Aegisthus.
Addendum: In other versions of this story, Iphigenia was saved at the last minute by Artemis, who replaced her with a deer and spirited her away. We should definitely also note that Clytemnestra was later killed by Orestes to avenge the murder of Agamemnon.