Things That Go Squeak in the Park

Just in time for Halloween, Police Captain Alexander Moffat uncovers a series of murders. The body count grows by Thanksgiving. A motive is as obvious as it is unconvincing. Otherwise, if this is the work of a psychopath, he or she is not interested in claiming credit and there is little hope of stopping the next murder.
Moffat, “stalwart and a man of integrity,” uses post-9/11 government data-gathering to question dozens of innocent people. The destruction of a California Black Oak called Old Ironbottom to make room for a new road points in one direction. Psilocybe cubensis mushrooms and a thirty-three nanometer calicivirus point in two others. The most intriguing question is: what went squeak in the park?
Captain Moffat struggles to solve the mystery by Christmas. Meanwhile he and his wife Jean, newly appointed guardians of a troubled but lovable teen, confront his worrisome secret.