ON "48 HOURS MYSTERY": A TRAGIC VACATION ENDS IN DEATH AND THEN A CONVICTION, BUT WILL A LEGAL TWIST SET THE KILLER FREE?

SATURDAY, SEPT. 8 (10:00 PM, ET/PT)

To everyone involved, the murder of Shelley Tyre seemed like a closed case when her husband David Swain was convicted of the crime. The story should have ended there, reports Troy Roberts in this updated edition of 48 HOURS MYSTERY: Shelley's Last Breath; however, it was far from over. Tyre died in 1999 when a scuba diving excursion went terribly wrong while she and Swain were vacationing in the British Virgin Islands. Initially, the cause of death couldn't be determined. Then police had enough to charge Swain with killing her by ripping her air supply off while they were 80 feet below the surface. He was convicted of murder and sent to jail. But then, as Roberts reports, just when it seemed Tyre's family would gain the closure they needed, a legal twist changed everything and continues to haunt them today.