It was after the then 28-year-old smashed the supermarket worker Mr Bick over the head with a hammer and strangled him with a shoelace.
Hunnisett, who, it is understood, now identifies as a woman, was cleared of a separate murder in 2001 after a retrial revealed that 81-year-old vicar Rev Ronald Glazebrook had sexually abused him.
Four months after his release Hunnisett created a “hit list” to rid the world of paedophiles, and made Mr Bick his top target.
That was despite there being “not a shred of evidence” that Mr Bick was a paedophile.
Mr Bick had instead separated from his partner and used social media and dating sites to meet young men.