Scuba shop owner David Swain and his wife of six years, Shelley Tyre, traveled to Tortola in 1999 for what was to be a romantic Caribbean getaway.
Only Swain made it home. Tyre drowned while scuba diving in what authorities in the British Virgin Islands initially called an accident.
A civil jury in 2006 found Swain responsible and awarded her parents millions in damages, prompting Tortola authorities to reopen the case.
Prosecutors plan to cite circumstantial evidence - including the damaged state of Tyre's scuba equipment and Swain's behavior after her body was found - in the upcoming criminal trial.