| Name | Character | Episodes |
|---|---|---|
| Hugh Bonneville | DCI Brian Boyce | 6 |
| Dominic Cooper | Edwyn Cooper | 6 |
| Jack Lowden | Kenny Noye | 6 |
| Sean Harris | Gordon Parry | 6 |
| Emun Elliott | Tony Brightwell | 6 |
| Charlotte Spencer | Nicki Jennings | 6 |
| Stefanie Martini | Marnie Palmer | 6 |
| Sean Gilder | DI Neville Carter | 6 |
| Amanda Drew | CS Cath McLean | 6 |
| Tom Cullen | John Palmer | 6 |
| Daniel Ings | Archie Osborne | 5 |
| Ellora Torchia | Sienna Rose | 5 |
| Peter Davison | Assistant Commissioner Gordon Stewart | 5 |
| Silas Carson | Harry Bowman | 5 |
| Sophia La Porta | Kathleen Meacock | 4 |
| Ruth Bradley | Isabelle Cooper | 4 |
| Adam Nagaitis | Micky McAvoy | 4 |
| Robin Laing | Garth Chappell | 4 |
| Dorothy Atkinson | Jeannie Savage | 4 |
| Chris Coghill | Neil Murphy | 4 |
| James Nelson-Joyce | Brian Reader | 3 |
| Vernon Dobtcheff | Matteo Constantino | 3 |
| Christopher Goh | Bank Manager Sam | 3 |
| Hadley Fraser | DCI John Fordham | 3 |
| Justin Edwards | PC Dave | 2 |
| Danny Webb | Billy Jennings | 2 |
| Sam Spruell | Charlie Miller | 2 |
| Dorian Lough | Donnie | 2 |
| Micah Balfour | Keith Potts | 2 |
| Lily Knight | Jackie McAvoy | 2 |
| George Russo | Young Policeman Jack | 2 |
| Frankie Wilson | Brian Robinson | 2 |
| Nicholas Farrell | Jim Clark | 1 |
| Angus Miller | Shuggie | 1 |
| Amerjit Deu | Doctor | 1 |
| Ann Mitchell | Sadie | 1 |
| Anthony Calf | Michael Corkery QC | 1 |
| Ian Pirie | Capitaine Siegrist | 1 |
| Teresa Banham | Henrietta Dickson | 1 |
| Josef Altin | Robert Wright | 1 |
| Richard Durden | Henry | 1 |
| Kieron Jecchinis | Freddie Hook | 1 |
| Nicholas Moss | DI Stan Owen | 1 |
| David Horovitch | Judge | 1 |
| Simon Chandler | Judge Instrell | 1 |
| Julian Wadham | Rufus McHugh QC | 1 |
| Marcus Garvey | Potts' Customer | 1 |
| Joanna Brookes | Mrs. Dennis | 1 |
| Nick Sampson | Nicholas Purnell QC | 1 |
| Will Keen | Hugh Vincent QC | 1 |
| Bob Cryer | PC Dylan George | 1 |
| Jake Fairbrother | Sergeant | 1 |
| Komal Amin | Jury Forewoman | 1 |
| Walter van Dyk | Swiss Judge | 1 |