DCI Joanne Davidson

Joanne Davidson is a senior detective heading a murder inquiry, sharp-suited, controlled, and clearly good at her job. She runs her team with brisk authority and gives nothing away in interview rooms or press conferences. When AC-12 starts circling her investigation, she meets their questions with calm, practiced composure.

Kelly Macdonald plays her with an unreadable stillness that keeps you guessing scene to scene, never tipping her hand toward guilt or innocence. The writing withholds motive as long as possible, forcing you to read her through tiny cracks in that professional armour rather than exposition, which makes every glance count.