When a wealthy socialite died after falling down the stairs, the eye witnesses said one thing and the evidence seemed to indicate another. To find out what really happened, investigators turned to forensic science, a physicist and an expert in accident reconstruction.

It's usually easy to determine how a criminal entered the crime scene. But in this case, it was far from clear. It looked like the killer vanished into thin air...and perhaps he had.

How unlucky could one man be? His wife had taken her own life, and his college sweetheart had killed herself in much the same fashion fourteen years earlier. Investigators had to determine if this was a bizarre coincidence, or an attempt to get away with murder... twice.