This is the first book in Ed McBain's long running police procedural series 87th Precinct. McBain would continue writing the ongoing series for half a century until 2005, the year of his death.
Someone is killing cops with a 45 calibre handgun. Steve Carella and the rest of the precinct have to find the killer before he kills again. Carella and Teddy are unmarried still and between the exhaustive investigation the pair try to snatch enough time together to decide on a date for the wedding.
As with quite a few of his books McBain makes good use of the weather conditions. You can almost feel the heat throughout. The last time I read one of these it was to the other polar extreme, with the city literally freezing in the depth and dark of winter. What really makes 87th Precinct books work though is the to and fro between the cops, the banter, some of it digging into the investigations or just the mix of everyday talk of a bunch of guys doing a day to day job, friendships, rivalries - real dialogue. McBain doesn't let the plot rule him. He takes time to develop characters and aspects of the city that sometimes have little or nothing to do with the central plot line. It's all canvas for big the picture. Don't expect summarised forensic reports either. For example if Carella gets a lab or ballistic report expect to hear it line for line. With this being the first book there's quite a lot of technical and scientific stuff to cover too. Fingerprints - here comes a breakdown of the chemical process that results in finger prints being created. It's just one of those signature elements that makes the series what it is.
Cop Hater isn't going to be the best book in the series but it does serve as a great introduction. The book was adapted for a 1958 movie of the same name starring Robert Loggia in the Carella/Carelli role.