An Alienist was an old term to describe a psychiatrist (a person who studies alienated people) and given that the start of the nineteen hundreds was to turn medical science on its head, this little tale takes us back to the origins of how and why it changed, by developing the process of psychiatry (or to be more precise behavioral science) with the analysis of a story about a Serial Killer roaming the rooftops of New York City, to murder and disfigure male child prostitutes that he has kidnapped for some strange reason, told through the eyes of New York Times journalist - John Moore, as he recalls this period of his life and which he wishes to commit to the page.
Moore is called to a crime scene by a friend of his, Dr. Laszlo Kreizler, the Alienist, to help him with an enquiry. They hook up with the police commissioner, Theodore Roosevelt and Sara Howard, the first woman police officer in New York, to investigate the murders along with two 'new age' brother detectives with a scientific bent - Marcus and Lucius. The problem is that the city does not care about the murder of child prostitutes, new policing techniques and Dr. Kreizler has some unorthodox views about metal illness that do not get him much respect in the city. Using Kreizler's ideas about the psychology of the killer the team decides to "profile" the killer to see if they can track him down before he commits the next murder. The Alienist - for all intensive purposes - is about the complex process of developing that profile and this is where the strength of the book really is and is main reason why you will enjoy reading it.
Apart from that deductive element The Alienist is really a run-of-the-mill "hunt the serial killer" type clichéd material. It does not really move outside of anything we have seen or read before (the analysis of the sexual orientation of killer is akin to that of what we have seen before in Silence of the Lambs) , but it does do exceptionally well in the psychology of criminal behavior department and to be honest you do not really get a chance to see this in 'fiction' much which gives the every day Joe Soap a chance to learn a bit about the early days of forensics and psychiatry.
For instance, one of the detectives manages within 24 hours of examining a murder victim to find that the killer uses a huge hunting knife and procures the very same knife by conducting cutting tests with various types of knifes that he has purchased around the city. These little forensic type discoveries are a joy to read and then when applied to the actual profile they are developing, helps take the case one step further. Here they are dealing with a man they have never met, who is cunning and smart and yet by using science and logic are able to track him down even though they do not have the techniques we have today like fingerprinting, DNA testing and security video tapes. So there is a struggle there in the book which sort of explains how the minority must go against the majority sometimes in order to advance mankind. It is all great stuff.
Carr does a good job of creating a tense atmosphere with vivid descriptions of a late 1800s New York City with all its political corruption, street violence and the gangster owned parts of town. He also does not shy away from describing the more grotesque parts of the story (various mutilations are covered in EXTREME detail along with a final act that is quite chilling), so this can be X-rated material at times and hard to stomach - however the English is first rate and a thrill to dive into the dictionary now again without breaking the flow of the story.
In spite of this The Alienist does have some negatives for all its positives. The first is that the motives for the killings are never fully explained and many loose ends are left untied - specifically how and why the killer did what he did. So even though the amazing detective work helps to find the killer, the whole psychology element really does fly out the window and you realize that in many ways you have been had. The story is about catching the killer and putting him out of commission, but Carr focuses a lot on developing the profile of the killer only to pull the rug out from us in the end in a sort - "I guess we will never really know sort of way" and that can annoying for some. I can get over some plot devices and story elements that are little corny or some parts that are farfetched (really just Hollywood suspension of disbelief type plots) but the lack of cohesion in the end really took a star of this thing in a big way. This is not a good call given the time you will spend reading and learning about the profile they are creating. I am sure those who have little contact with crime fiction will find the book more than satisfactory but those with experience may not like where it all leads.
Don't let that put you off though. It is still a hell of a good read - just don't spend too much time trying to work things out because it will be a futile attempt by the time you turn the end pages. Having said that though I would certainly check out this author's other works just on the bases of having read this one. The bottom line is that this is a descent crime drama with a detailed exploration of early psychiatry and forensic work.