This well-written book reminded me of Martin Cruz Smith's Arkady Renko series, and a movie based on the true story of a Soviet era serial killer called Citizen X. 
 The detail about living in the 1950's Soviet Union is very convincing, and characters nicely developed. The book's sole flaw is the reveal of the killer's motives and the ending, which come across as something you'd see in a bad Hollywood thriller, but overall this was a fascinating story.