Allen was born as Anthony John Angel on 11 June 1934 in Torbay, though grew up largely in Bournemouth.
[1] In July 1968, Allen was convicted of bigamy and other crimes, receiving a suspended prison sentence.
In 1970, Allen was convicted of burning three bags of mail that he was meant to deliver, and spent one year in jail.
Allen claimed that between 25 and 30 May 1975, he and his wife had an argument and she left, returning two days later to take the children.
[2] Allen was tried and convicted of the murder of his second wife and his two children (although no bodies were ever found), and sentenced to life imprisonment in 2002.