| Name | Character | Episodes |
|---|---|---|
| Neil Dudgeon | DI Duncan Warren | 9 |
| Ken Stott | DCI Red Metcalfe | 9 |
| Michelle Forbes | Susan Metcalfe | 6 |
| Frances Grey | DS Kate Beauchamp | 6 |
| Art Malik | DCS Michael Emerson | 4 |
| Kieran O'Brien | Eric Metcalfe | 4 |
| Beatie Edney | Grace Eccleshall | 3 |
| Helen McCrory | Dr. Rachel Price | 3 |
| Russell Tovey | Robbie McManus | 3 |
| Harriet Walter | Professor Robb | 3 |
| Hugo Speer | DI Jack Price | 3 |
| Maxine Peake | DS Vickie Clarke | 3 |
| Eamon Boland | Henry McArdle | 3 |
| Pip Torrens | DCI Walmsely | 2 |
| Tom Ellis | Dr. Philip Ryder | 2 |
| Marsha Thomason | DS Mel Palmer | 2 |
| Vincent Regan | DI David Wilby | 2 |
| Marc Warren | DCI Joseph Walker | 2 |
| Rory Kinnear | Stewart Dean | 2 |
| Shaun Dingwall | Daniel Jameson | 2 |
| Emily Joyce | Anna Marchent | 2 |
| Clare Holman | Jaine Ellis | 2 |
| Michael Maloney | Carl Henderson | 2 |
| Sam Troughton | Thomas Stone | 2 |
| Paul Copley | Ian Fleet | 2 |
| Kika Markham | Emma Giardello | 2 |
| Alun Armstrong | DCI Charlie McIntyre | 2 |
| Catherine Russell | Clare Fenton | 2 |
| Rufus Jones | TV Reporter | 2 |
| Andrew Pleavin | PO Darrell Teague | 2 |
| Serena Gordon | Alison Reeves | 2 |
| Edward Woodward | Rev. Stephen Hedges | 2 |
| Daniel Ryan | DS Terry Hedges | 2 |
| Jamie Draven | DS Jez Clifton | 2 |
| Patrick Baladi | Jonathan | 2 |
| Ciarán McMenamin | Daniel Hughes | 2 |
| David Quilter | Brian Herd | 2 |
| Terence Budd | Welch | 2 |
| Laura Greenwood | Leah Wallace | 2 |
| Howard Crossley | D.C. Freeman | 2 |
| Michael Bertenshaw | Gov. William Houseman | 2 |
| Raymond Trickitt | D.C. Nixon | 2 |
| Valerie Lilley | Maureen Fleet | 2 |
| Anton Lesser | Samuel Waite | 1 |
| Ophelia Lovibond | Lucy Waite | 1 |
| Aleksandar Mikic | Alexi Pasovic | 1 |