May 1988. Detectives investigate the discovery of the body of 86-year-old Alice Covington inside her car outside the city of Raleigh, North Carolina. The remote location and the 'vampire-like' burn marks on Covington's neck immediately raise their suspicions. Investigators hit the streets for clues. They learn the elderly woman was seen struggling with a female nurse before she disappeared. A bank-teller reports she cashed a $2500 cheque on Covington's account when she and a nurse pulled up at drive-thru bank. Detectives question Covington's friends and identify homecare nurse, Carlette Parker, as the prime suspect responsible for her demise. When they research her background, they discover she has a history of stealing from those in her care.

1984. Tampa, Florida. Police discover the bodies of multiple murder victims. All show signs of horrific sexual abuse. A serial killer is on the loose. The only pieces of evidence investigators have connecting the murders are minute red fibres that they believe come from the killer's car. When the same fibres are found on teenage rape victim Lisa McVey, police get a vital breakthrough. Despite being blindfolded and repeatedly raped, the teenager's testimony helps police identify her attacker. He is Bobby Joe Long an X-Ray technician with a history of deviant behaviour while working in Tampa's hospitals. When detectives present Long with evidence linking his car to the murders, he confesses and describes each kill in detail.

Missouri, December 1984. St Louis Police are called in when a farmer discovers the body of a young man, Sean Cavaness. He's been shot twice in the head and left to die at the side of the road. Investigators immediately begin searching for leads to uncover who could have murdered the man and are shocked when they realise that their prime suspect is none other than the victim's father, Dr John Dale Cavaness. 'Dr Dale' as he's known has established himself as a hero in his hometown of Eldorado, Illinois where he regularly offers his medical services for free to those unable to pay. Locals cannot believe that this charming and kindly doctor could be capable of murdering his own son. But when police delve into his past, they reveal a shocking history of violence and a desperate doctor, battling with financial problems.

When young carer, Suzette Trouten goes missing, Kansas police are drawn into the dark world of one of America's most despicable killers. Former X-ray technician and medical consultant, John Edward Robinson appears to be an upstanding member of the community. But investigators soon discover he is not who he seems. Behind the mask of respectability, he hides a history of crime, lies and depravity. Detectives uncover a seemingly innocent connection between Suzette and Robinson. She moved state to take up nursing work contracted through his company. But there's something else. She and Robinson both participate in BDSM - bondage, domination and sadomasochism. They know each other from online forums, catering for those with extreme sexual tastes. Police discover Suzette isn't the only missing person connected to Robinson.

When retired nurse Joyce Brannon is discovered brutally murdered, Chicago investigators face one of their toughest challenges yet. There is no forensic evidence, no fingerprints and no murder weapon. The murder appears without motive and it seems that whoever killed Brannon has committed the perfect crime. But when the FBI learns that the victim has been issued with a subpoena to give evidence against a suspected fraudster, they have their suspect. Dr Ronald Mikos is a highly successful Chicago podiatrist who has been under investigation for eighteen months by Chicago's Department of Health and Human Services. This charming and highly successful doctor is the highest earning podiatrist in the state and investigators suspect that he could be swindling the federal government for hundreds of thousands of dollars. But when they attempt to uncover his crimes, they hit a brick wall. Mikos' patients are loyal to their doctor and no-one is prepared to testify against him.