| 1 | Antoinette | Conway | Detective on the Murder Squad |
| | Stephen | Moran | Antoinette's partner on the Murder Squad, aka Steve |
| | | O"Kelly | Superintendent of the Murder Squad |
| | Bernadette | | Administrative assistant for the squad |
| | | Breslin | Detective on the Murder Squad |
| | J.P. | Dooley | Garda on duty at the murder scene |
| | Sophie | Miller | Lead crime scene tech |
| | Aislinn | Murray | Murder victim, trendy young
woman; receptionist at cleaning services company, aka Ash |
| | | Cooper | Pathologist |
| | Lucy | Riordan | Aislinn's good friend |
| | Rory | Fallon | Aislinn's prospective date for the evening of the murder, owner of a book-shop |
| | Louis | Crowley | Aggressive journalist for The Courier |
| 2 | | Costello | Senior detective in the squad for
the first few months of Antoinette's assignment |
| | Laurence | Flannery | Friend of Lucy's, published a theater history book |
| | Mrs. | Murray | Aislinn's mother, emotionally unstable from desertion by her husband, now deceased |
| 3 | | O'Gorman | Murder squad detective |
| | | King | Murder squad detective |
| | | Winters | Murder squad detective |
| | | Healy | Murder squad detective |
| | | Quigley | Murder squad detective |
| | Joe | McCann | Murder squad detective |
| | | O'Neill | Murder squad detective |
| | | Roche | Murder squad detective |
| | | Stanton & Deasy | "Floaters," cops who brought in a witness |
| 4 | | Kellegher & Reilly | "Floaters," cops who checked CCTV footage & escorted Rory back home |
| 5 | | Meehan & Gaffney | "Floaters," cops who carried out the door-to-door investigation of the case |
| 7 | Gary | O'Rourke | Cop in Missing Persons division, friend of Antoinette |
| 8 | Desmond Joseph | Murray | Aislinn's father who disappeared in 1998 |
| | Vanessa | O'Shaughnessy | Nurse who used Desmond's taxi service, emigrated to England |
| 9 | Fleas | | Undercover cop, friend of Antoinette from training school |
| | Goggles | | Criminal, former informant for Fleas, incarcerated for drug trafficking |
