In a city not unaccustomed to murder as a daily staple of print and broadcast journalism , someone has found a new method of killing : a serial killer is terrorizing New York City with a series of brutal murders more apropos of the fourteenth century than the twentieth century . The killer is using caltraps —a medieval device for laming horses on a battlefield. The NYPD enlists the aid of Dr. Bradley Davison of Queens College, a noted authority on medieval weaponry , to assist in the investigation . While serving as guest curator of the Arms of the Tower exhibition at the Metropolitan Museum of Art, Brad Davison puts together the clues to identify the killer leading to a stirring final battle in the equestrian hall of the museum. The Caltrap Murders is the first in a series of four murder mysteries featuring Brad Davison , his future wife Libby Karistos and Detective Lieutenant Mag Goldman and his squad of NYPD homicide detectives . Each mystery brings to life the historical period of the Middle Ages with all its social, cultural and military complexities.