Sitting in the apparently safe lobby of his father's gun club, a teenage boy is mysteriously shot dead. Ballistics, laser technology, scale models and forensic animation reveal the bullet's amazingly tragic path - and who was responsible.
A woman mysteriously disappears, and police detect blood on her bedroom carpet. Testing with the chemical Luminol reveals a room awash in blood spatter. DNA testing confirms the victim's identity. Can police find her body - and the killer?
Early one morning in a deserted area outside of Phoenix, a motorcyclist discovered the body of a young woman. She had been beaten, bound, strangled and possibly raped. The nearby plants would tell investigators more about the killer than any other single piece of evidence.
Shortly after Thanksgiving in 1987, an intruder broke into a residence in Arlington, Virginia. That crime launched a new era in police investigations: DNA evidence and psychological profiling helped catch a serial killer and free an innocent man.
Philadelphia, the birthplace of the United States, played host to millions of tourists and hundreds of gatherings as America celebrated its 200th year of independence. History was made that summer of 1976 - not because of the bicentennial, but because of the mysterious death of 34 people at an American Legion convention. The groundbreaking investigation by the CDC had to explain why dozens inside a hotel - and some who just walked by outside - all got sick.
On the night of May 22, 1992, Betty Wilson returned home after a meeting. She walked up the stairs to the bedroom and discovered her husband, lying in a pool of blood. Jack Wilson had obviously been murdered... but how? And by whom? Even the experts couldn't agree.
Eleven children in an elementary school in Phoenix contracted childhood leukemia; nine of them died. And in Guilford, Connecticut, five people were diagnosed with brain tumors on a street where there were only nine homes. Two towns, two cancer clusters, two mysteries. The investigation answered some questions, but raised many more.
Between 1985 and 1988, 18 people were choked, molested and left for dead in the remote desert mountains of California. The only witnesses were the insects - and they also proved to play an important role in solving the crimes and bringing the killer to justice.
In 1985, 121 people in South Dakota and Minnesota were struck with a mysterious illness. There had been only one outbreak like it, and when it happened then, no one could figure out why. This time, disease detectives would use scientific tools to unravel a mystery centered on the technique of a butcher.
In 1991 after a weekend earning wilderness merit badges, a boy scout ended up with slight fever and diarrhea, sending him to the hospital. His kidneys started shutting down and his diarrhea turned into hemorrhaging, leaving doctors puzzled.