Seasons & episodes

A report on the 1973 murder of a Massachusetts inmate believed to have been the Boston Strangler, a man suspected of 13 women in the 1960s. Also: a man's search for the half-sister he only recently discovered he had. (Repeat)

Reports include unexplained encounters with angels; a woman's quest to find her missing husband. Also: a man who disappeared in 1993 while scuba diving near the entrance to the Mississippi River gulf outlet. (Repeat)

Reports on the authenticity of the Shroud of Turin; the search for two missing French sailors, last seen in the Atlantic; unexplained encounters with angels; a woman's search for biological father. (Repeat)

"Mysteries of Alien Beings" reports on four men who say they were abducted while on a fishing trip in Maine's Allagash Wilderness, and includes research by Harvard psychiatrist John Mack. Also: a pilot's alleged UFO sightings in Kazakhstan; efforts to locate a nurse who reportedly helped with autopsies of alien beings that emerged from the wreck of a UFO.