Season 4

[The Cross-Border Butcher] When a man is found dead in a San Diego motel, minus his leg, police initially believe it's the result of a car accident. But evidence soon casts suspicion on the involvement of 79-year-old Dr. John Ronald Brown, an underground gender reassignment surgeon since the 1970s.

[Doctor Death] On November 22, 1998, Dr. Jack Kevorkian assists the death of a terminally ill patient live on TV. Kevorkian is tried for murder, and the nation is split. Is Kevorkian a saint who helps end patients' suffering, or a crack-pot who loves the limelight?

[The Deadly Deep End] When Samira Frasch is found dead at the bottom of the pool, police begin to investigate her podiatrist husband. Did he stage the scene to hide his crime? Or could someone else spotted by a witness be to blame?

[My Darling Dentist: The Deadly Drug Dealer] The suicide of former Maryland beauty queen Sarah Harris, whose body is found by her boyfriend, oral surgeon Dr. James Ryan, leaves her loved ones in shock. But when her sister turns detective, she finds evidence that suggests Sarah had not died by her own hand. Detectives set about proving who is guilty of her murder.

[The Dangerous Dermatologist] Police are called to a home in the town of Wenham, MA, after a woman is shot in the back by a stranger at the front door. Mother of three, Karen Sharpe dies later that night in the hospital. Investigators soon uncover that Karen is in the midst of a multi-million dollar divorce from a violently abusive husband.

['Rescue Rambo'] At Delmenhorst Hospital, Germany, administrators notice death rates in their intensive care unit have risen sharply. Suspicions fall on nurse Niels Högel aka 'Rettungs Rambo', who turns out to be Germany's most prolific murderer since WWII.

[The Teen Carer Who Killed] When a resident dies at BaptistCare Bethel care home in Albany, Western Australia, it's assumed she passed away peacefully. But an autopsy reveals horrific injuries. In the frame is carer Jacob Hoysted, but can this quiet, young man really be a brutal murderer?

[Too Lazy to Care, Too Easy to Kill] When an elderly care home resident is discovered dead at Aidan House in Bensham, Gateshead, staff members sense that something is amiss. A murder investigation begins into a nurse at the home, but when she becomes a victim of violent attacks, could someone else be responsible?

[Kiss of Death] A modus operandi that mimics natural death works to the advantage of a north Texas serial killer who preys on elderly victims. His murderous death toll is suspected of having amounted to 22 before a sinister clue leads to his capture.

[Prescription for Murder] Motivated by greed, a small-town Oklahoma doctor writes a prescription for death, flooding her community with a lethal cocktail of drugs, and leaving a trail of victims in her wake.