If you’re an actor playing a police detective, it helps if your best friend is a cop. Fern Sutherland, who plays Kristin Sims in The Brokenwood Mysteries, modelled her character – “a woman genuinely wanting to make a difference in the world the best way she knows how” – on her high-school pal, a constable in New Plymouth. Sutherland prepped for the leading role by tagging along with her friend on the beat, before the first series aired in 2014. Sutherland also spoke to Taranaki detectives about their work, saying at the time they had “Literally. Seen. It. All.” Today, an episode of the New Zealand-made The Brokenwood Mysteries has millions of viewers across the world. Ahead of its fourth season, Sutherland took our Sunday Grill.