Unsolved Mysteries Wiki

Mark Adams

Real Name: Mark Adams
Aliases: None known
Wanted For: Escape
Missing Since: 1986


Details: Mark Adams was a gunman who had committed a string of armed robberies. His stealing came to an end on the night of August 17, 1979, when he and two other gunmen had finished a holdup and were discussing dividing their loot in a forest. Unbeknownst to them, the woods were near a baseball diamond where three high school students had been drinking beer. Frightened at being overheard, the gunmen confronted the students and ordered them to leave, as well to hand over any money or valuables they had in their pockets. When one of the boys, sixteen-year-old Michael Ridenour, refused, Adams shot him execution style, and Ridenour died instantly.
Eventually all three gunmen were captured by California state troopers. Mark Adams was found guilty of grand theft and first-degree murder. For his brutalities, he was remanded to the maximum security San Quentin prison, which had gained the reputation as the most notorious prison in California after Alcatraz was decommissioned in 1963, and houses such notorious criminals as Charles Manson.

Mike Ridenour

Surprisingly, the regimented life of San Quentin seemed to have a positive effect on Adams. Prison guards recall Adams as never being in violation of the rules, and taking advantage of volunteer shops, academic classes, chapel services, or anything available that could get him out of his cell. Mark Adams would have been considered eligible for parole in 2007. One afternoon in 1986, he told a guard he had access to an area of the prison he normally was not allowed, showing authorization papers to meet with the dental officer. The guard, who normally did allow inmates safe passage in order to proceed to the infirmary, did not suspect anything out of the ordinary. A couple of hours later, Adams was not in his cell during the routine 8-hour check. San Quentin was placed on lock-down, but there was no sign of Adams. Authorities were perplexed at how Mark Adams managed to flee San Quentin, a prison many call "escape proof," and drew three theories:

  1. Adams had managed to scale one of the 25-foot walls, despite being earmarked as "kill zones", in which guards are authorized to open fire on inmates. This theory is the least believable as guards are posted at battlements and would have likely spotted Adams, but the positions were predictable and the possibility could have occurred that Adams could have taken advantage of possibly distracted guard who considered his posting routine.
  2. About 20 to 30 service vehicles enter and exit San Quentin each day, such as garbage trucks and food service vans. Said vehicles are subject to rigorous inspection, but Adams could have hid in one part of a vehicle where he was undetected.
  3. Adams acquired and donned civilian clothes, mingled with people at the visitor's center, and made his way to freedom when the visitors were ushered out by guards. This theory is the most believable as it would have been the easiest for Adams to accomplish.

Extra Notes: The case first aired on the November 16, 1988 episode. The case was also featured on America’s Most Wanted.
Results: Captured. In 1993, Adams was captured in Humacao, Puerto Rico, thanks to tips from America's Most Wanted. At the time, he was living under the name "Michael Jacobson" with his wife, former prison supervisor Elsie Diaz. After his arrest, he was returned to San Quentin. He was shot and killed by guards during a fight in the prison exercise yard on March 7, 1994. His family later sued San Quentin prison and its director, claiming that the guards used excessive force. In December of 1998, the family was awarded over $2 million.