The inter-relationships between serious types of crime have been neglected. Focusing on those convicted of arson (n=45,915), blackmail (n=5,774), kidnapping (n=7,291) and threats to kill (n=9,816) in England and Wales (1979-2001), we examine the specialisation and sequencing of these crimes in relation to the risk of subsequent homicide. All four offences have a heightened likelihood of subsequ...