The family of a university lecturer, murdered by a man he trusted in a calculated plot, say they don't want anyone to go through what they have.
Peter Farquhar, from Maids Moreton in Buckinghamshire, was befriended by Ben Field, an assistant churchwarden. The pair were eventually engaged, but it was all a con.
Field poisoned Mr Farquhar with drink and drugs to inherit his money. Last week, a jury found him guilty of murder. He's still waiting to be sentenced.
Benjamin Field, 28, was found guilty at Oxford Crown Court for the murder of Peter Farquhar, 69, in the village of Maids Moreton, Buckinghamshire.
During the trial, the court heard how Field embarked on a campaign drugging, deceiving and defrauding the victim in the lead-up to his death.
Mr Field's co-accused, magician Martyn Smith, 32, was found not guilty.
The pair were both cleared of a charge of conspiracy to murder Mr Farquhar’s close neighbour Ann Moore-Martin and Field was also acquitted of her attempted murder.
He had convinced both he was in a relationship with them, but was really manipulating and torturing the pair.
Field killed Mr Farquhar by making his death look like an accident or suicide.
Peter's brother and sister-in-law say they want to use their story to help protect others from being deceived in the same way.
Peter's brother Ian says: "There's a lesson to be learnt. If you are somebody who has now become kind of lonely, a little bit vulnerable, and you've lost your confidence about speaking, or if you're a relative of that person, then actually you've got to be brave here. If somebody comes in like some kind of guardian angel, then be very careful. Ask questions and get an outside opinion. If you see a loved one who's been vibrant and full of life, and then things are going wrong, find out what it is, because you could save their life."
- Watch the full interview here: