Salvation in Death (In Death, #27) - J.D. Robb
For me these stories always look similar but this time we had the first murder and a second one looking like a serial killer, but Eve was super smart and discovered that in reality the second was just a copycat. Different because usually her investigations are related homicides, but this time she had a difficult time discovering the reason to kill a priest.
Eve had a difficult time with the religion part, mostly because she just doesn't understand the cult and some rules, but Roarke was helpfull and she even got the help of a priest trying to do the right thing. For me the investigation was nice and the end during the interrogation Eve showed why she's the best.