The Son of Sam would become the most notorious killer in New York's history. Shooting women or couples parked in lover's lanes, the mystery killer spread terror through the streets of the metropolis, leading young women to cut and dye their hair for fear of becoming the killer's next victim. Writing to the police and press, the Son of Sam would claim to relish his 'work' and that he was programmed to kill. A massive manhunt would lead police to David Berkowitz - a lonely young man, adopted at birth, who claimed he was commanded to do the devil's work by a neighbour's barking dog. So was the Son of Sam driven by demons? Wreaking a bitter revenge fuelled by mental illness? Or was he programmed from birth to be a serial murderer?