The 26th season begins with an investigation into the murders of two teens that occurred 32 years ago.

The 2012 death of American engineer Shane Todd in Singapore is investigated. His death was officially ruled a suicide, but his parents believe he was murdered.

The 2008 death of Leslie Mueller is investigated as her husband, Frederick Mueller, stands trial for murder for the second time. The first trial resulted in a hung jury.

The mysterious life of Christian Gerhartsreiter, who pretended to be Clark Rockefeller of the famous Rockefeller family, is investigated, as are allegations that he murdered John Sohus in 1985.

An update on the Michael Skakel murder case involving the death of Martha Moxley in Greenwich, Conn., in 1975.

The 2011 murder of 18-year-old Lauren Astley is investigated. Her ex-boyfriend, Nathaniel Fujita, is the prime suspect in her death.

The 2006 murder of Nicole Pietz in Seattle is investigated. The victim's mother believes she knows who committed the crime.

The 2003 murder of Heather DeWild in Colorado is investigated. Her husband, Daniel, and his twin brother are chief suspects in the case.

The 2008 murder of model Juliana Redding in Santa Monica, Cal., is investigated, and the DNA evidence suggests that a woman was the killer.

An interview with David Camm who was wrongfully convicted of murdering his wife and children in 2000.