Season 1 (2005)
7.33 avg 6 episodes 7.3 → 7.5 46 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Fred West | 7.3 | 58 |
| 2 | Dr. Harold Shipman | 6.8 | 47 |
| 3 | Jeffrey Dahmer | 7.8 | 57 |
| 4 | Myra Hindley | 7.3 | 44 |
| 5 | The Washington Snipers | 7.3 | 32 |
| 6 | Ivan Milat | 7.5 | 27 |
Seasons
Season 2 (2010)
7.40 avg 6 episodes 7.2 → 7.4 45 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Ted Bundy | 7.2 | 48 |
| 2 | John Wayne Gacy: The Killer Clown | 7.4 | 46 |
| 3 | Richard Trenton Chase: The Vampire of Sacramento | 7.6 | 33 |
| 4 | Charles Starkweather: The Teenaged Spree Killer | 7.5 | 29 |
| 5 | Albert DeSalvo: The Boston Strangler | 7.3 | 31 |
| 6 | Aileen Wuornos: The Highway Killer | 7.4 | 26 |
Season 3 (2011)
7.55 avg 6 episodes 7.4 → 7.2 45 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Pee Wee Gaskins Jr.: Meanest Man in America | 7.4 | 26 |
| 2 | Gary Ridgway: The Green River Killer | 7.7 | 34 |
| 3 | Edmund Kemper: Co-ed Butcher | 7.9 | 37 |
| 4 | Richard Ramirez: The Night Stalker | 7.2 | 36 |
| 5 | Dennis Nilsen: The Kindly Killer | 7.9 | 32 |
| 6 | David Berkowitz: The Son of Sam | 7.2 | 28 |
Season 4 (2012)
7.20 avg 6 episodes 7.1 → 8.0 46 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Beverley Allitt: The Angel of Death | 7.1 | 24 |
| 2 | Colin Ireland: The Gay Slayer | 6.5 | 28 |
| 3 | The Manson Family | 6.9 | 34 |
| 4 | Kenneth Bianchi & Angelo Buono Jr: The Hollywood Hillside Strangler | 7.5 | 24 |
| 5 | Herbert Mullin: The Serial Killing Saviour | 7.2 | 27 |
| 6 | Dennis Rader: The Bind and Torture Killer (BTK) | 8.0 | 37 |
Season 5 (2013)
7.37 avg 12 episodes 7.3 → 7.6 45 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Donald Neilson: The Black Panther | 7.3 | 25 |
| 2 | Peter Sutcliffe: The Yorkshire Ripper | 7.6 | 27 |
| 3 | Hadden Clark: The Cross-Dressing Cannibal | 7.3 | 28 |
| 4 | The Thriller Killers | 7.2 | 24 |
| 5 | Thor Christiansen | 7.5 | 25 |
| 6 | Twisted | 7.7 | 21 |
| 7 | Doug Clark & Carol M. Bundy: The Sunset Strip Killers | 7.2 | 25 |
| 8 | Patrick MacKay: The Devil's Disciple | 7.2 | 25 |
| 9 | John Linley Frazier: The Killer Prophet | 7.0 | 24 |
| 10 | Cary Stayner: The Yosemite Park Slayer | 7.2 | 23 |
| 11 | The Briley Brothers | 7.6 | 20 |
| 12 | Paul Bernardo and Karla Homolka: The Schoolgirl Killers | 7.6 | 29 |
Season 6 (2014)
7.19 avg 12 episodes 7.2 → 7.6 44 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Gerald and Charlene Gallego: The Love Slave Killers | 7.2 | 23 |
| 2 | Tony Costa | 7.1 | 23 |
| 3 | Richard Cottingham: The Times Square Ripper | 6.9 | 25 |
| 4 | Cleophus Prince Jr: The Clairemont Killer | 7.3 | 22 |
| 5 | Robert Napper: The Green Chain Rapist | 6.9 | 21 |
| 6 | Levi Bellfield: The Bus Stop Stalker | 7.1 | 20 |
| 7 | John Duffy and David Mulcahy: The Railway Killers | 7.1 | 24 |
| 8 | Sean Vincent Gillis: The Other Baton Rouge Killer | 7.3 | 26 |
| 9 | Timothy Spencer: The Southside Strangler | 7.3 | 26 |
| 10 | David Gore and Fred Waterfield: Killing Cousins | 6.9 | 25 |
| 11 | David Carpenter: The Trailside Killer | 7.6 | 20 |
| 12 | Bobby Joe Long | 7.6 | 23 |
Season 7 (2015)
7.42 avg 6 episodes 7.6 → 7.3 44 min avg
| # | Title | Rating | Votes |
|---|---|---|---|
| 1 | Allan Legere: Monster of the Miramichi | 7.6 | 24 |
| 2 | Bill Suff, 'The Riverside Killer' | 7.6 | 18 |
| 3 | Charles Albright: The Eyeball Killer | 7.8 | 24 |
| 4 | Peter Moore: The Man in Black | 6.9 | 22 |
| 5 | Robert Reldan, 'The Charmer' | 7.3 | 21 |
| 6 | Trevor Hardy: The Beast of Manchester | 7.3 | 14 |
