I have never before written about someone who differed so sharply from his reputation as Al Capone,"" concludes Bergreen (As Thousands Cheer: The Life of Irving Berlin, 1990, etc.) in this shallow life of Public Enemy No. 1. As Bergreen tells it, Capone was scapegoated for America's failure to abide by Prohibition and was a victim of anti-Italian prejudice. This is far too reductionist. Bootlegging was just one part of Scarface Al's underworld empire, which also included gambling, prostitution, and massive corruption of Chicago's police, politicians, and press; and while there was surely a glut of anti-Italian sentiment, most Italians managed not to be driven by it into a life of crime. To be fair, Bergreen does not deny that Capone was awash in blood, and he has discovered medical files detailing the mobster's cocaine use and syphilis-induced megalomania. He also mentions government files on an older brother who changed his name and became a legendary Prohibition agent, and cites scores of people who testify to Capone's impulsive generosity. Repeated statements about moral complexity, however, explain nothing about why Capone became infamous even in brawling Chicago. Bergreen notes that he conducted more than 300 interviews, but mere quantity is inadequate without standard biographical procedures. For instance, he claims that Capone desperately yearned to forsake racketeering while he sought sanctuary from a murder rap in Lansing, Mich., but the source for this information is cited pseudonymously. Moreover, Bergreen never attempts to prove a Capone confidant's claim that Eliot Ness was on the take (in fact, he portrays Ness as a skirt-chasing, alcoholic publicity hound). Even in an age of revisionism that has raised the stock of the likes of Jimmy Hoffa, Bergreen's insistence on a kinder, gentler Scarface is breathtaking chutzpah -- the kind the mobster might have employed.