Expert Witness - Series 4

Eighty-five million acres make up the National Park System, and only 33 special agents nationwide are responsible for investigating crimes that occur on this public land. This documentary series follows the uniquely qualified team that leads the investigations as they seek to bring law and order to some of America’s most rugged and remote landscapes, tackling a new case each season.

The fascinating cases of every day, seemingly average moms, wives and girlfriends accused of murder. Did they really do it? And if so, why?

Uncover the heart-wrenching true stories behind crimes that transcended headlines and became part of popular culture. Exclusive first hand interviews reveal shocking twists, new evidence, and unexpected resolutions.

Real crimes, disease outbreaks and accidents around the world are solved by experts using scientific laboratory analysis which helps them find previously undetectable evidence. Brilliant scientific work helps convict the guilty and free the innocent.

Monsters can be found lurking behind any innocent smile and on any street corner in America. Never-before-seen-video footage stares straight into the eyes of these killers who hide in plain sight. Anyone can be a monster.

Investigates a wide range of historically compelling topics and the mysteries surrounding each including the Titanic, D.B. Cooper, Roswell, John Wilkes Booth, and more. Fresh, new evidence and perspectives will be showcased, such as never-before-released documents, personal diaries and DNA evidence.

Eerie encounters, bizarre disappearances, haunting events and more perplexing phenomena are explored in this chilling investigative docuseries.

What happened in the final days of Gabby Petito's life? In this gripping true-crime series, her loved ones reveal the untold story of her tragic murder.

Natural World is a nature documentary television series broadcast annually on BBC Two and regarded by the BBC as its flagship natural history brand. It is currently the longest-running series in its genre on British television, with more than 400 episodes broadcast since its inception in 1983. Natural World is produced by the BBC Natural History Unit in Bristol, but individual programmes can be in-house productions, collaborative productions with other broadcasters or films made and distributed by independent production companies and purchased by the BBC. Natural World programmes are often broadcast as PBS Nature episodes in the USA. Since 2008, most Natural World programmes have been shot and broadcast in high definition.

These are the terrifying tales of the unwanted neighbors who turn home sweet home into home sweet hell. A look inside the lives of horrific neighborly disputes and what happens when a simple issue turns into the worst night of a family's life. Do you really know who lives next door? This true-crime series tells the chilling tales of those with the misfortune to unwittingly take up residence within a stone’s throw of a psycho or killer.