The Truth of All Things Book

When Deputy Marshal Archie Lean is called in to investigate a prostitute's murder in Portland, Maine, he's surprised to find the body laid out like a pentagram and pinned to the earth with a pitchfork. He's even more surprised to learn that this death by "sticking" is a traditional method of killing a witch.
Baffled by the ritualized murder scene, Lean secretly enlists the help of historian Helen Prescott and brilliant criminalist Perceval Grey. Although skeptical of one another's methods, together the detectives pursue the killer's trail through postmortems and opium dens, into the spiritualist societies and lunatic asylums of gothic New England. Before the killer closes in on his final victim, they must decipher the secret pattern to these murders—a pattern hidden within the dark history of the Salem witch trials.