Shetland S4 EP2

Pérez investigates who attacked Thomas, and circumstances point to Benny Ray, who'd been a witness at Thomas's trial. Sally's friend Jo Halley tells Sandy she saw Sally arguing with someone in Norwegian at the folk festival. Pérez's stepdaughter Cassie starts volunteering at a wildlife sanctuary run by Donna Killick, mother of Sally's boyfriend Alan. A DNA test on a hair found on Lizzie Kilmuir's scarf reveals it came from a relative of Alan. However, tissue from Donna's deceased husband indicates that he is not Alan's father. Tosh interviews employees at Forst energy, a Norwegian company that Sally had been investigating for unsafe practices. Alan tells Cassie that he realized Sally had been lying to him before her death. Pérez learns that Thomas's trial was unethical, partly because Benny Ray was a police informant paid by Drew McColl.