This is a remarkable, revelatory exploration of the world's most extreme cases of mass murder by two of the UK's most respected true-crime experts. From it, a significantly consistent pattern emerges of the person who commits multicide: almost always male, a loner lacking in social skills, not able to form stable relationships. Bearing a general grudge against society or blaming a particular individual, he determines to seek a fanatical revenge. Over 200 notorious cases include: Eric Harris and Dylan Klebold, two heavily armed students who opened fire at Columbine High School, Colorado, killing 13; Michael Ryan, perpetrator of the notorious 'Hungerford Massacre', in which 16 people were shot dead, including his own mother Brenda Spencer; a rare instance of a female mass murderer, who opened fire at a junior school, killing 11, 'Because', she said, 'I don't like Mondays'; Jeremy Bamber, the country boy found guilty of killing five members of his family; Julio Gonzalez, who, after a row with his girlfriend, set fire to the Happy Land social club, killing 87 people; The Supreme Truth Cult, who released nerve gas in subway trains in Tokyo, killing 12 people; and, Timothy McVeigh, responsible for the deaths of 168 people in the Oklahoma bombing.