McDermott is half-Korean, and was adopted by an American couple from Korea.
McDermott had previously filed for bankruptcy and had received a court order to pay overdue child support to his former wife, actress Yvette Nipar. Nipar and McDermott were married on March 1, 1992 when Nipar was four months pregnant. They divorced 15 months later on June 30, 1993.
He disappeared from a fishing charter boat off San Pedro, California, on June 30, 2005. The 48-year-old McDermott was a passenger on the fishing boat Freedom which had left from the San Pedro marina for an overnight fishing trip. Twenty-two passengers and three crew members on board gave contradicting reports of whether he was actually on board or had left at the conclusion of the trip. His absence was apparently unnoticed until July 6 when he failed to attend a family event.
An extensive search and investigation has failed to explain the disappearance but the circumstances have fueled speculation that he faked his own suicide.
The case has been featured on America's Most Wanted.
Fox News Network reported on June 4, 2006, that some witnesses claim to have seen McDermott alive and well in Mexico. The prevailing theory is that he in fact died at sea, but many believe that he staged his disappearance in order to avoid court proceedings brought by an ex-wife concerning child support payments.
Olivia Newton-John has since remarried (2008).