Bad Blood is a 1981[2] British-New Zealand thriller film set during World War II in the small town of Koiterangi (now Kowhitirangi) on the west coast of the South Island of New Zealand, and is based on the factual manhunt for mass-murderer Stanley Graham.

[3] The script was based upon Manhunt: The Story of Stanley Graham, by H. A. Willis (Whitcoulls, 1979) and adapted by New Zealand-born Andrew Brown.

[4][5][6][7] In October 1941 Stan Graham, a Westland smallholder, develops a persecution complex and starts to threaten his neighbours, in which he is encouraged by his wife.

A manhunt is organised, involving police, army and local home guard members, and finally they track him down.

Although considered risky when released, Bad Blood is now regarded as a New Zealand film classic.