Derrick Wilson is the security guard at Kentigern Gardens who was on duty the night of Lula Landry’s tragic fall from her third-story balcony.

He is described as “a heavily built West Indian man.” “Muscle as well as fat swelled the sleeve of his security guard’s sweatshirt; his hair was close-cropped and he was clean-shaven, with fine almond-shaped eyes.” (The Cuckoo’s Calling, Part 2 Chapter 6)

On the night of Lula’s death, Wilson had a bad case of diarrhoea and was in the toilet for 10 minutes, during which time Lula fell to her death. He rushed out of the toilet after hearing Tansy Bestigui screaming. She had come running down the stairs, shaking uncontrollably and saying someone had pushed Lula off her balcony. Derrick went outside to see after Lula and then upstairs to try and find the killer, whom he suspected was Evan Duffield. After finding nobody in the building, Wilson deduced that she had, after all, committed suicide.

During the Lula Landry investigation, Cormoran Strike interviews Derrick Wilson in the Phoenix Cafe.