A pair of Somali men were sentenced to life in prison on Monday for their roles in the hijacking of a yacht that left all four Americans on board dead. One of the men argued he had unsuccessfully tried to persuade his fellow pirates that the two women on board should be released.

The owners of the Quest, Jean and Scott Adam of Marina del Rey, Calif., along with friends Bob Riggle and Phyllis Macay of Seattle, were shot to death in February several days after being taken hostage several hundred miles south of Oman. They were the first Americans to be killed in a wave of piracy that has plagued the Gulf of Aden and the Indian Ocean in recent years.