Luisi became a licensed private detective in 1906, at the age of 21. His father, who had been a secret agent of the Italian police, tutored the young man for what was to become his fifty-year career as an insurance investigator. In the course of his search for lost, stolen, or strayed property (mostly furs or jewelry), Luisi worked on cases involving Lord and Lady Mountbatten, Pearl White, and many other celebrities. Having done a legitimate favor or two for Arnold Rothstein, Luisi was able to utilize the gambler's tipoffs on several occasions. Not the least of his exploits involved members of the original Murder, Inc. Luisi strongly advocates tightening of investigative procedures before issuing property-insurance policies. He relates several ""inside jobs"" in which sufficient prior checking would have disclosed an applicant's questionable status as an insurance risk, for financial or psychological reasons. He estimates that ""at least one-quarter of all robberies, burglaries, and disappearances of jewelry reported by jewelers and their salesmen are fakes,"" and suggests that the precedents of litigation force the insurance companies to be too liberal in settling doubtful claims.