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TV series

Diabolical

Latest episode

S3 E10 · Evil Sister Act

About Diabolical

Diabolical is a crime and documentary TV series that premiered on Investigation Discovery on January 1, 2018. It has 3 seasons and 30 episodes so far and is still airing new episodes. The latest episode, Season 3 Episode 10 "Evil Sister Act", aired on May 12, 2020.

Like trying to decipher the value of a book without ever opening it, judging a person by his or her outward appearance can be a mistake. Someone may look perfect on the outside, but even the most kind-hearted soul has a dark side looming. "Diabolical" is a docuseries that delves into the minds of murderers, asking a simple question: "Why did they do it?" The acts were committed with extreme premeditation -- many were months or even years in the making. Tension builds in each episode as law enforcement taps into the methods of devious masterminds, aided by insights from forensic psychologists and psychiatrists as well as criminal profilers.

  • Crime
  • Documentary

Last updated

Episodes

30 episodes · 3 seasons

Season 1

2018 · 10 episodes · Last episode: 8 years ago

Diabolical Season 1 release dates →
  1. E10

    10. Living Off The Dead

    Finale

    George Kalomeris is a family man who looks after the less fortunate in his community, then a dying man fingers Kalomeris as the shooter, and police discover a monster more diabolical than anyone could ever imagine possible.

  2. E9

    9. Weeping Widow

    After losing her husband in a tragic accident, a God-fearing Cindy McKay claims she has to bend the law to pay off his illicit debts; authorities soon realize that Mckay is a criminal mastermind.

  3. E8

    8. Accident Waiting To Happen

    Single mom Rainey Morin thinks she has found her one and only soulmate in Robert Kowalski. However, beneath his bright veneer is a dark history threatening to wreak havoc upon her life and those around her.

  4. E7

    7. Family Or Foe

    A young family is on an evening stroll when suddenly terror strikes. Nothing seems to add up during the investigation, it is not clear if it is random violence or a mastermind at work and the truth will take years to emerge.

  5. E6

    6. Mother Of All Murders

    Janet Lynn Mickey dreams of starting her own family and marries college football star Darrell Tyburski; plans change after the young couple begins having children, leading them down a very dark path.

  6. E5

    5. Best Of Friends

    After sneaking out to attend a party, 19-year-old Jose Najera returns home to find both of his parents dead in their bedroom. It is unclear if it is a random killing or a botched robbery.

  7. E4

    4. Who Lies Beneath

    Valuing wealth more than love, Michelle Donohue casts aside good men before meeting Mr. Right who gives her a taste of her own medicine and sends her down a murderous path.

  8. E3

    3. 'Til Death Do We Part

    Lyle and Carol Kopenskey are high school sweethearts who marry after graduation; after 40 years of marriage, one of them becomes involved in an extra-marital affair that leads to cold-blooded murder.

  9. E2

    2. Lying For Love

    Temptress Cathy Cousin moves in next door to devoted family man Tim Koile, wrapping him around her finger and convincing him to satisfy her every whim no matter how diabolical.

  10. E1

    1. Mistress Roulette

    Married family man Dr. Adam Frasch has a booming practice, and he loves to spend money on houses, automobiles and exotic dancers; ultimately, the doctor will reap what he sows in deceit and jealousy.

Season 2

2019 · 10 episodes · Last episode: 7 years ago

Diabolical Season 2 release dates →
  1. E10

    10. When All Else Fails

    Finale

    After her home is invaded and her husband murdered, Shaunna Dodd recounts her harrowing ordeal at gunpoint; however, when investigators dig deeper, they uncover a tale of lies, infidelity and shady characters who have wandered into the Washoe Valley.

  2. E9

    9. Murder Is No Accident

    A vivacious 33-year-old drowns in the middle of a crowded lake. The investigation untangles a dark, nefarious past that includes theft and multiple murders and detectives must take extraordinary measures to catch the killer.

  3. E8

    8. A Life Of Lies

    In Prichard, AL, loving father Re'Mano Campbell is found murdered in his home; it takes the cunning wit of local investigators to unravel the mystery of who murdered him.

  4. E7

    7. The Rich Get Richer

    Penny Knell is admitted to a special care facility, where a devious mastermind is waiting to prey on vulnerable people; when Penny's family gets ensnared in her web, the consequences will be fatal.

  5. E6

    6. Control Freak

    Donna Scrivo hasn't seen her adult son, Ramsay, in days, and she's worried; she alerts the police, but days pass with no sign of him anywhere; then the discovery of a severed head and body parts along a highway reveals an act of shocking violence.

  6. E5

    5. Queen Of Deception

    In Susanville, CA, a beloved police officer is found dead in what looks like an apparent suicide, then detectives launch a full-blown murder investigation and zero in on the officer's wife as a possible suspect.

  7. E4

    4. Recording Evil

    Gina Coccia comes home from work to discover the bodies of her girlfriend, Lynn, and Lynn's nephew, Ronnie, shot and stabbed on the kitchen floor; the investigation leads police to a terrifying act of betrayal.

  8. E3

    3. Someone's Lying

    On April 17, 2015, a Virginia hunter makes a grisly discovery in the woods, finding a woman with an execution-style gun shot wound to the back of her head.

  9. E2

    2. Who Needs Enemies

    A cold morning in December starts off like any other, then a farmer finds the body of a dead woman; what seems like a rape and murder case turns into a conspiracy, and someone's diabolical nature is soon revealed.

  10. E1

    1. Mother Of All Lies

    In 2015, Detective Scott Sanderson finds himself investigating one of the strangest cases of his career, involving a missing woman and her newborn; before long, he uncovers a diabolical scheme that will destroy the lives of everyone it touches.

Season 3

2020 · 10 episodes · Last episode: 6 years ago

Diabolical Season 3 release dates →
  1. E10

    10. Evil Sister Act

    Finale

    When Samuel Johnson Jr. suddenly vanishes, investigators find themselves face-to-face with two sisters who know something; through a series of interrogations, they reveal an elaborate murder plot meticulously engineered by a puppeteer.

  2. E9

    9. Killer Track Record

    Three women die of the same mysterious illness, and the hunt is on to prove their deaths were no accident; investigators don't realize they're being played for fools by a sinister killer lurking undetected.

  3. E8

    8. Caught In the Cover-Up

    In West Bloomfield, MI, a simple affair between two coworkers turns complex as the two lovers are willing to do anything, even commit murder, to protect their darkest secret.

  4. E7

    7. Devil Wears False Eyelashes

    Three men die over a span of a dozen years, with no suspicion of wrongdoing and no files charged. But when a deadly car explosion rips through downtown Pensacola, FL, a new investigation begins; all suspicion points toward just one person.

  5. E6

    6. Teach Me To Kill

    In Las Vegas, a beloved father of four is found dead in his car; he's been bound, gagged, and asphyxiated. Witnesses lead detectives to a local man named John Brian Ray, but this troubled man is just a pawn in the game of a criminal mastermind.

  6. E5

    5. Sins of a Mother

    In 1994, Lake Orion, MI, is rocked by a murder; at first, the crime is a mystery -- but in a small town where everyone knows each other, rumors start flying. Police soon expose a strange and twisted plot that no one saw coming.

  7. E4

    4. Lie For Me

    Air Force veteran Michael Giles disappears along with his savings of $206,000 and detectives find a that Kwaneta Harris has been draining his accounts.

  8. E3

    3. Masking Evil

    A burning car is found by the side of a highway on the same night a single mother of two is reported missing; the two events are related and connecting the dots leads investigators to a notorious criminal who has been hiding in plain sight.

  9. E2

    2. Hands That Rob the Cradle

    In early 1980, two eerily similar crimes occur 400 miles apart; they both leave young mother dead and an infant child stolen; years later, police unravel a plot so cold-blooded, it leaves everyone even seasoned homicide detectives in utter shock.

  10. E1

    1. Daddy's Little Nightmare

    In 2017, Federal Heights, CO, is filled with fear when 69-year-old veteran Bill Mussack is reported missing, gone without a trace; police act fast to uncover a diabolical killer with a heinous plot before the malicious murderer strikes again.

Cast & crew

  • William Cataldo

    Self - Assistant Prosecutor, Macomb County, MI

  • Kerrie Droban

    Self - True Crime Author

  • Leslie Rule

    Self - Co-Author, 'Lying in Wait'

Diabolical FAQ

When is the next episode of Diabolical?

A date for the next episode of Diabolical hasn't been announced yet. Follow Diabolical in the Streambay app and you'll be notified as soon as a new episode airs.

When did the latest episode of Diabolical come out?

The most recent episode of Diabolical, Season 3 Episode 10 "Evil Sister Act", aired on May 12, 2020.

How many seasons of Diabolical are there?

Diabolical has 3 seasons with 30 episodes in total.

When did Diabolical first air?

Diabolical first aired on Investigation Discovery on January 1, 2018.

How do I get notified when new episodes of Diabolical are released?

Download the Streambay app, follow Diabolical, and you'll get a push notification the moment each new episode is released.

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