Shipman may be among world's worst serial killers

Estimates that Harold Shipman may have murdered 297 patients during his 24-year career as a doctor make him one of the world's most prolific serial killers.

The worst known serial killer was an Indian man called Behram, who strangled at least 931 victims with his yellow and white cloth strip, or ruhmal, in the Uttar Pradesh district of India between 1790 and 1840.