An excerpt from Sir James McNeish's book "The Mask of Sanity":
"Deep down I believe he (David) knows he is guilty. He has given us several clues, for example in a letter written in 1996 expressing satisfaction at the way the judge treated him. "He was very kind to me during the trial" David Bain wrote to a friend on 15 February 1996, "seeming to see the pain I was going through." This is not a confession. It is however, many will think, an admission at the very least, remembering that the judge sentencing David Bain told him he acted "with a significant degree of cunning and premeditation", it indicates that David Bain thought he had been given a fair trial."
Page 221; "The mask of Sanity" By James McNeish.
The recipient of the letter from David Bain writes [20.4.97], "At first I thought it a bit odd as the judge...had not minced words and more or less said David had planned it all-to get the family 'fortune' and start a new life-with the sympathy of everyone. Today I suddenly relised that if he felt the judge was 'seeming to see the pain I was going through' could imply that the judge had hit the proverbial nail on the head and in his summing up of the case lies the essential truth of the murders.
Conclusion. If David was innocent, but found guilty of murdering his entire family, and was told by the judge at sentencing that he had acted with a significant degree of cunning and premeditation, I would hardly think David would be likely to express satisfaction at the way the judge had treated him.