I picked up `Death Squad' (Dell, December 1977) with the hope that it would be a New York City take on the cops-as-vigilantes theme of the 1973 movie `Magnum Force'. In actuality, `Death Squad' is a standard-issue police procedural, featuring author Kastle's recurring `Sergeant Ed Roersch' character.
Ed Roersch is of course modeled - like so many other 70s police procedural characters - on Wambaugh's archetypal Bumper Morgan. Readers should know ahead of time that Roersch is middle-aged, on the verge of retiring, one step away from a coronary, overly fond of good food and beers, fiercely loyal to his buddies on the force, cynical but true-hearted, dedicated in his own rough way to recognizing that America is unjust to black people, and maybe also to Puerto Ricans, and even maybe `fruits' (i.e., gays), etc., etc.
`Squad' starts off with a trio of homeboys, joyriding in a stolen Firebird, creating mayhem on East 52nd street in Manhattan on a warm summer night. Among the victims is a police captain, whose presence on the street in the early morning hours is something of a mystery.
The task of heading the investigation of this high-profile crime is handed to Roersch, who soon learns that what appears to be a simple case of opportunistic street crime may in fact be something deeper and darker. For there is a team of rogue cops operating within the NYPD, and they won't hesitate to eliminate any fellow officer who can't be persuaded to look the other way.....
Author Kastle wrote a sizeable number of pulp fiction novels in the 60s, 70s, and 80s, most of these in the Harold Robbins vein of softcore porn / melodrama. `Death Squad' is competently written, if not particularly original in terms of its theme and setting.
I suspect most readers will figure out who the chief villains are well before the book's midway point, and they will also recognize that the book is overly long, and several sub-plots could have been excised without detracting from the main narrative.
Contemporary readers will no doubt be impatient with the regular interludes in which the characters muse and agonize over their moral and personal failings, but these types of expositions were part and parcel of 70s crime novels, in the era before the admonition to `show, don't tell' governed fiction writing.
If you're looking for a `gritty' police procedural with appropriate levels of mid-70s cynicism, then `Death Squad' will fit the bill. However, if you're looking for a thriller or action novel based on the Rogue Vigilante premise, you are better off watching `Magnum Force' all over again.