CHRIS CUOMO INVESTIGATES: WHO WOULD BEAT AND LEAVE A YOUNG WOMAN FOR DEAD, AND HOW DID THEY MANAGE TO SNEAK HER OUT OF A HOTEL WITH NUMEROUS SECURITY CAMERAS?

Exclusive Report Airs on a Special Two-Hour "20/20" Friday, April 1, 9:00-11:00 p.m., ET

It was a case that stumped police: who beat Inna Budnystka, a young, blond cruise line worker in a Florida hotel, snuck her out of the hotel and left her for dead in a deserted cul-de-sac? Surveillance cameras captured her entering the elevator at the Miami hotel where she'd been staying, but she was never seen leaving again. When she regained consciousness, her statements to police were contradictory and confusing. There was no shortage of suspects, including an older man who was once a friend of the victim but who'd been arrested after a battery incident against her at a nightclub, and a hotel manager whose interests in the victim went beyond his professional duties. After all the leads ran cold and the cops ran out of theories, they agreed to let a colorful private investigator named Ken Brennan run with the case. The mystery became an obsession for Brennan, and the theory he came up with about another suspect was so outlandish it sounded like a joke � until DNA evidence and months of investigative work proved him right. Chris Cuomo's exclusive report airs on a special edition of "20/20" on FRIDAY, APRIL 1 (9:00-11:00 p.m., ET) on the ABC Television Network.

Vote: Can You Pick the Best Clue in Florida Attack Case? Guess Which Clue Helped Detective Ken Brennan Find an Elusive Violent Criminal: http://abcnews.go.com/2020/vote-pick-best-clue-florida-attack-case/story?id=13251195

Video: Finding One Man in Hotel Full of Suspects. How a tough-as-nails private detective tracked down an elusive violent criminal: http://abcnews.go.com/2020/video/finding-one-man-in-hotel-full-of-suspects-13248249

"20/20" is anchored by Elizabeth Vargas and Chris Cuomo. David Sloan is executive producer.