DAYTON, Ohio — Vacation memories will be savored for years. One might recall a sunset, a meal or a museum. I’ll always remember particular books I have read.

I perused Amy Tan’s novel “The Bonesetter’s Daughter” on our hotel balcony to the sound of waves crashing into the Mexican coast below.

There was the hotel in Tuscany where I guffawed over Helen Fielding’s “Bridget Jones’ Diary” as mounted policemen clattered over the cobblestones down in the alley.

Three recent novels could provide stimulating vacation reading. One is a legal thriller, the others are police procedurals. All three have plots drenched in moral ambiguity.

“The Twelfth Department,” by William Ryan (Minotaur Books, 342 pgs., $25.99)

William Ryan’s series featuring Capt. Alexei Korolev are set in Moscow during the 1930s. As “The Twelfth Department” opens, an influential medical researcher has been found dead in his luxurious apartment. Korolev is asked to lead the police investigation. He’s just getting started when he is pulled off the case by the fearsome NKVD, the Soviet secret police.

It seems the researcher had been conducting secret experiments upon street urchins. These unfortunates were getting their memories erased with electric shocks. When Korelev is asked to resume investigating the case, he has acquired a personal interest, his own son has vanished and he fears the boy might become a guinea pig for this sinister research. This story takes place in 1937 as Stalin’s show trials were underway and some former heroes of the Bolshevik Revolution were being silenced forever. You can almost taste the fear.

“The Man From Berlin,” by Luke McCallin (Berkley, 435 pgs., $15)

I’m an ardent admirer of Philip Kerr’s series featuring the detective Bernie Gunther. So I was pleasantly surprised to discover military intelligence officer Capt. Gregor Reinhardt has many things in common with Gunther. Both fictional characters were homicide detectives in Berlin who went on to solve crimes under the auspices of the German Army during World War II.

In “The Man From Berlin” Reinhardt is stationed in German-occupied Croatia when he is asked to investigate the murder of a woman who had been a prominent Croatian journalist. Reinhardt is a participant in a secret plot to assassinate Adolph Hitler. His attempts to solve this murder become rather complicated due to aggressive intercessions by Germans, Italians, Serbs, Croats, Bosnians and Tito’s Partisans.

“The Collini Case,” by Ferdinand von Schirach (Viking, 191 pgs., $25.95)

Ferdinand von Schirach is a German lawyer who has penned a couple of knockout collections of short stories entitled “Crime” and “Guilt.” His latest effort, “The Collini Case,” is more of a novella, at less than 200 pages, but it is just as compelling as his earlier offerings.

This story opens with the murder of a prominent German industrialist in a fancy Berlin hotel. The killer, Fabrizio Collini, is an elderly Italian who had retired after a long career at a Mercedes-Benz factory.

Collini admits he did it yet he won’t explain his motives. His defense attorney, Caspar Leinen, is just barely out of law school. It is up to Leinen to explicate the devastating chain of circumstances that led up to this crime. It all began during World War II.