A serial killer policier set in Philadelphia with a male lead, recovering and only partly back on duty, and a female partner who
has sufficient seniority to head up the field team investigating the crimes. This is the second book with this pair, in the first
of which the female is a rookie, with a third featured at the close of this book. It provides something of a contrast between the normal slow routine of checking out leads, known criminals and limited witness statements with the use of informers - in this case a woman who had been badly hurt by one of the prime suspects in the current case - and flashes of inspiration, made mainly by the recovering male detective. He also becomes involved with the female informer. Relying rather on a mix of red herrings and coincidence, the book moves along fairly well but is not overly convincing in the end.