Paul Novak's outwardly heroic persona as a post-9/11 paramedic concealed a dark side that culminated in the brutal murder of his estranged wife Catherine in their Sullivan County home.
Malcolm Webster's wife, Claire, died in a car crash in a remote part of Scotland, and he was apparently inconsolable. When his second wife, Felicity, almost died in similar circumstances and money is missing, suspicions were raised.
Kathy Augustine was a politician serving in the Nevada Senate. Shortly after her husband of 17 years died from complications of a stroke, she married Chaz Higgs, a critical care nurse whom she met while he was caring for her late husband.
Something was wrong at DaVita dialysis center in Lufkin, East Texas, with a huge increase in code blues. Patient after patient was taken to the nearest hospital, many succumbing to their injuries.
William George Davis, a nurse in Tyler, Texas, was just 32 when he began a reign of terror over patients recovering from heart surgery. Prosecutors claimed that Davis had at least eleven victims, of whom seven died.
When Eric Lloyd died at home, his wife claimed it was from natural causes. Marie Whiston had been looking after him between nursing shifts at their local hospital and was anxious to attribute his death to ill health.
From February to April 1991, Beverley Allitt's reign of terror at Grantham Hospital led to the deaths of four children and serious harm to many others. Her background revealed troubling signs of Munchausen's syndrome.
Within two years of Dr Lisa Tseng starting her career in Rowland Heights, Los Angeles, the demographic pattern of her patients dramatically changed, with largely young men travelling long distances to seek pain medication.
All Jessica Patel from Middlesbrough wanted was a loving husband and a family of her own. She married her first love, Mitesh, but soon her dreams were shattered when he proved psychologically and physically abusive.
Dr Harold Shipman, a respected GP, murdered some 250 patients. Despite suspicions raised by colleagues, it took years for the authorities to catch up with him. We reveal a shocking pattern of abusing trust.
In little more than a year after Reta Mays started work as a nurse's assistant in the VA center, there were 21 suspicious deaths. The FBI launched an investigation, leading to the exhumation of some of her victims.
Dr Bob Neulander found his wife, Leslie, covered in blood in the bathroom, having apparently fallen. Initially, her death was ruled an accident, but due to local rumours the DA reopened the investigation.
Over the course of just a few months, Vickie Jackson murdered at least ten people. An investigation found a suspicious syringe in Jackson's trash, and bodies were exhumed to test for the lethal drug.
