By Dennis Drabelle, The Washington Post The publicity sheet for Martin Cruz Smith’s engaging new novel boasts that the author “does extensive research for all of his books,” including in this case “four trips to Italy.” Extensive but not always freewheeling. At the outset of his career, Smith dazzled Sovietologists by parlaying his background reading and one brief visit to Russia into “Gorky Park” (1981), which was praised for its accurate insights into the heart of the Soviet police state. Smith has since written seven more novels featuring the hero of “Gorky Park,” Arkady Renko, a Russian cop with a conscience.