DORSET Police is to hold an internal review into the way it handled investigations after the force was alerted to threatening text messages sent by the homeless man who went on to murder the Rev John Suddards and a retired teacher.
Before the murders he sent messages to a friend, Michaela Rowsell, warning her he was going to hurt someone and target the church.
She contacted Dorset Police, which is now looking into how it responded.
Farrow, 48, was imprisoned for life on Friday for the "sadistic" and "horrific" murders of Mr Suddards at his vicarage in Thornbury in February and widow Betty Yates at her cottage in Worcestershire the previous month.
In the text messages sent just days before the death of Mrs Yates, Farrow wrote to Mrs Rowsell, whom he had nicknamed piggy: "I've already started my work and won't stop until I'm caught. You don't and never knew just how disturbed I am. You will soon know the truth and the church will be the first to suffer and I don't lie about what is about to happen.
"As I say it was always going to end like this. I'm surprised the police have not been to see you but they soon will. So f*** you, the church and the system. You can all go to hell. Watch the news piggy because you will know it was me."
Mrs Rowsell, who testified for the prosecution during Farrow’s month-long trial at Bristol Crown Court, received the chilling messages on New Year’s Eve.
She told jurors she had met Farrow in spring 2011 when she was helping out the homeless at an evangelical church in Bridport, Dorset.
Mr Suddards was found on February 14 lying in his hallway. He had been stabbed seven times in his shoulder, chest and abdomen.