Black River by Matthew Spencer

When a teenage girl is found dead at a private school in Sydney, the authorities wonder if the death is the work of the BMK killer. The killer has already murdered two women. There are similarities—and some differences—in this latest case. Detective Sergeant Rose Riley is working with DCI Steve O'Neil. They also bring in forensic psychiatrist Farquhar to lend his expertise. In addition, Riley includes local reporter Adam Bowman because he has inside knowledge of the school. Bowman agrees to help the authorities with information and, in turn, Bowman will get exclusive access to the police's findings. In Black River, it's a race to uncover the killer before he claims another victim.