Watching the Ghosts - Book 4 in the Joe Plantagenet series

Boothgate House is a recently converted apartment building with a sinister past. Once an asylum for the insane, known as Havenby Hall, it was where serial killer Peter Brockmeister was sent on his release from prison. Detective Inspector Joe Plantagenet is drawn into the house's history when the daughter of a solicitor, who was investigating Havenby Hall's closure, is kidnapped. Joe wonders whether there may be a connection between the case and the building's disturbing past.
But as secrets come to light, Joe is forced to face an evil that threatens those closest to him.