Unsolved Mysteries

The show first aired on NBC from 1987 to 1997. The pilot episode was hosted by actor Raymond Burr. Karl Malden and Robert Stack were also hired to host further specials. When the series became a full-fledged television program in 1988, Stack became the full-time host. Unsolved Mysteries was also one of the few prime-time shows of its era to appeal to fans of the supernatural and used effective special effects to enhance tales of the unexplained.

In 1992, NBC aired a short-lived dramatized court show spin-off program called Final Appeal: From the Files of Unsolved Mysteries, also hosted by Stack. The premise of this program was to try to give the unjustly accused a final appeal for help, with the debut episode taking an in-depth look at the Jeffrey MacDonald case. The program was canceled after only a few episodes due to poor ratings.

The ratings for Unsolved Mysteries' had been steadily declining ever since it was moved from its original Wednesday evening timeslot to Friday evenings in the fall of 1994. At the end of the 1996–97 season, it was canceled by NBC. Upon the cancelation from NBC, CBS picked up the series for a tenth season. The first episode aired in November of 1997 as an Unsolved Mysteries special. When CBS canceled its Block Party line-up with shows such as Family Matters and Step By Step in the spring of 1998, the network moved the show to its Friday 9:00 pm timeslot. During the show's run on CBS, the series was limited to only six-episode seasons, and was airing only on a sporadic schedule.

When the series returned for its abbreviated 11th season in the spring of 1999, Stack was joined by actress Virginia Madsen for hosting duties in an attempt to boost its female audience.[15] But the effort failed, and CBS canceled the show soon afterwards. Later cable reruns of segments originally narrated by Madsen were re-dubbed with Stack's voice.

Lifetime Television, which had been airing re-runs of the NBC episodes since the early 1990s, had ordered a two-season run of new episodes which began airing in 2001. Consisting of a mixture of new and old cases, these episodes were produced between 2001 and 2002, and usually aired on weekdays between 11 a.m. and 3 p.m. The program ceased producing new episodes when Stack was diagnosed with prostate cancer in late 2002. He died of heart failure in May 2003.[16]

After Stack's death, old episodes continued to run in syndication on several television networks in the U.S., Canada, and Australia.

During some shows, callers gave tips to the telecenter. When the show was in active production, the number was displayed on the bottom of the screen at the end of each segment. When the show left active production following Stack's death and went into reruns, the number was removed and replaced with a P.O. box address.

According to Broadcasting & Cable, in 2007, HBO Distribution announced plans to bring back Unsolved Mysteries when the cable channel Lifetime's contract expired in 2008. The show featured a new set, a new logo, new music, and updates on old cases. In addition, actor Dennis Farina became the new host, as Stack had died five years earlier. The show debuted on Spike on October 13, 2008.[17]

This repackaged series run was criticized by fans for its presentation of past cases only, with no new case segments being produced. The existing segments were also edited to be shorter so the show could be expanded to present five cases in an hour rather than the four of the original series. Because the majority of the cases were now between 20 and 40 years old, the re-edited segments usually did not reference the years in which the events presented originally occurred. When updates for solved cases aired, Dennis Farina's voiceover would refer to cases "in a recent broadcast...", when the case may have already been solved during the show's original run or during the series' hiatus from 2002 onward. Unsolved Mysteries ended its run on Spike on April 27, 2010.

As of November 24, 2020, Oxygen Network airs 12 episode marathons of this version on Tuesdays from Noon ET/11:00 AM CT.

A 12-part reboot was announced by Deadline Hollywood on January 18, 2019. The series is being "refreshed" by Stranger Things executive producer Shawn Levy and his company 21 Laps Entertainment along with Cosgrove-Meurer Productions and Netflix. Cosgrove and Meurer are showrunners for the series, with Levy and Josh Barry being executive producers. Robert Wise is a co-executive producer, along with showrunner Dunn Meurer. Each episode focuses on a single mystery.[8] Cosgrove stated that the reboot would be "pure documentary style" and would have no host or narrator,[18] however an image of longtime host Robert Stack can be seen in the title sequence for each episode as an homage to his impact on the show.[19] The first six episodes of the new season became available to stream starting July 1, 2020.[20] In August 2020, it was reported that 13.7% of subscribers had watched the series over its first month.[21] An official Unsolved Mysteries weekly podcast was announced on October 21, 2020.[22]

In 1992, Unsolved Mysteries filmed in Texas and cast Matthew McConaughey to play a murder victim. This was one of McConaughey's earliest on-screen roles.[23] Cheryl Hines, Stephnie Weir, Bill Moseley, Ned Bellamy, Holmes Osborne, Scott Wilkinson, Daniel Dae Kim, David Ramsey, and Taran Killam also appeared on the program before receiving more notable work in Hollywood.[24][25][26] Hill Harper also appeared in an episode about a woman looking for a childhood friend whom she later discovered was indeed her sister.

• Comedian Blake Clark was interviewed in the "Comedy Store Ghosts" episode.
• Author James Ellroy appeared in an episode looking for the man who murdered his mother.
• Football player Reggie White appeared in an episode trying to find the arsonists who set fire to his church.
• Musician Henry Rollins and actor Dennis Cole both appeared to find the people responsible for the murder of Cole's son, Joe.
• Musician Ron Bushy appeared in a story about the disappearance of fellow Iron Butterfly bandmate, Philip Taylor Kramer.
• Musician Jon Bon Jovi was interviewed about the death of his personal manager's daughter, Katherine Korzilius.[27]