| Name | Character | Episodes |
|---|---|---|
| Richard Harrington | Luke French | 20 |
| Kieran O'Brien | Constable Robert Clifton | 20 |
| David Sterne | Desk Sergeant Edward 'Mac' McFadden | 20 |
| Kacey Ainsworth | Inspector Jenny Black | 20 |
| Tim Pigott-Smith | 20 | |
| James Hillier | Custody Sergeant Christian Young | 20 |
| Sara Powell | Rachel Barker (Crown Prosecution Service) | 20 |
| Jimmy Akingbola | Constable Neil Parker | 20 |
| Elaine Glover | Rookie Lucy Slater | 20 |
| Julie Cox | 3 | |
| James Thornton | 3 | |
| Anna Acton | 2 | |
| Simon Kassianides | 1 | |
| Luke Roberts | 1 | |
| Lee Turnbull | 1 | |
| Danny Sapani | 1 | |
| Chris Coghill | 1 | |
| Doreen Mantle | 1 | |
| Selina Giles | Sally Lewis | 1 |
| Derek Thompson | Charlie Fairhead | 1 |
| Jordan El-Balawi | 1 | |
| Rosie Marcel | 1 | |
| Rick Warden | 1 | |
| Janet Dibley | 1 | |
| Laura Greenwood | 1 | |
| Marcel McCalla | 1 |