A recovering alcoholic prone to depression, the stress Hole's mental health suffers is often a focus of the stories. He has few friends and often clashes with colleagues. While later recognizing his problematic behavior and leaving the police force, he continues to find reason to aid with new criminal investigations even when it endangers him and loved ones. The novels are frequent bestsellers. His mother, a descendant of the Sami people , died due to cancer while he was in his twenties.