Though less lurid than David Yallop's Deliver Us From Evil (1981), particularly regarding the physical details of Peter Sutcliffe's 13 murders of Yorkshire women from 1975 to 1980, this account adds little beyond deeper background on Sutcliffe's family--which apparently cooperated with Burn, but may not like the resuiting portrait. The Sutcliffes, Burn suggests, were an odd group. Father John appeared to have two personalities: outside the home he was a dapper amateur singer, cricket-player, and womanizer; at home, he had a ""foul temper"" (according to his son Carl) and a strange streak (he once impersonated another man over the phone to arrange an illicit rendezvous with his wife, then ordered their children to accompany him to the hotel to see her embarrassment). The two younger sons were ne'er-do-wells, one in and out of jail, the other a semi-vagrant who lived in the woods. From his father we learn that Peter, the oldest of five, was a timid and sensitive child with an aversion to sports and an unnaturally strong attachment to his mother. After leaving school he took a job as a gravedigger, and his customary abstraction ""started to deepen into what to his friends seemed like semi-trances."" Peter's main interests in life were motorbikes and cars, and eventually (somewhat to his family's surprise) he parlayed these hobbies into a well-paid job as a long-distance truck driver. Peter also found a girlfriend, Sonia Szurma, the daughter of Czech immigrants, whom he ultimately married--notwithstanding the ""unprovoked outbursts of rage and agitation"" that put her, for a time, in a psychiatric hospital--and whom his family appears to have disliked from the start (and vice versa). Just over a year after his marriage, Peter began the string of murders--mostly, but not all, of prostitutes--that terrorized the north of England for five years. Burn devotes relatively little attention to the police investigation of the case (which has been heavily criticized--Peter Sutcliffe himself was questioned eight times over several years before being arrested) or to the issue of whether the Ripper was insane (three psychiatrists said yes, a jury said no). Sidestepping these important areas would be more defensible if Bum's admittedly exhaustive research into Peter Sutcliffe's family background threw more light on the still-unanswered question: why did he do it? Disappointing.