The eldest daughter of Milly Dowler's killer Levi Bellfield has told of her sympathy for the teenager's family and said a jail sentence was "not enough of a punishment".
Writing to Milly's parents and sister, Bobbie Bellfield, 20, said it made her "sick" to think she was related to the murderer, whom she branded a "monster".
Levi Bellfield was jailed for life on Friday for murdering 13-year-old Milly as questions were raised about the adversarial nature of the trial system, which distressed the Dowlers.
In her open letter, published in the Sunday Mirror, Ms Bellfield said: "I'm writing to you because I want to say how sorry I am for what my dad has put your family through. I felt physically sick when I found out he had killed your daughter and I couldn't watch as you spoke outside the court about the hell you had all gone through to get justice."
Referring to comments made by Milly's sister, she added: "Gemma, I think you were right when you said 'a life for a life'. Being locked up is not enough of a punishment for what he has done." Ms Bellfield, who is one of four daughters born to the killer's one-time girlfriend Becky Wilkinson, says she cannot bring herself to call him dad.
On Saturday, a criminal barrister gave her backing to defence lawyers after the director of public prosecutions said he would examine how victims were treated in court following the Milly Dowler case.
Kirsty Brimelow QC said that she felt "the balance is right" and that lawyers needed to "go in fairly strong" during cross-examination of a witness.
The most senior police officer in the Milly case, Surrey Police chief constable Mark Rowley, criticised the "disgraceful lack of humanity" in the justice system following the ordeal suffered by the schoolgirl's family. But Ms Brimelow said that the need to persuade a jury of their client's innocence already placed a restraint on defence lawyers.
She told Sky News: "Barristers try very much not to be unpleasant to witnesses, not to be aggressive, because it is actually counter-productive to defending in a case. But we are in an adversarial system and sometimes perhaps things may well get carried away in court and cause distress."
Keir Starmer QC, the director of public prosecutions, said: "This trial has raised some fundamental questions about the treatment of victims and witnesses in the court process. Those questions require answers and we will be contributing to the review by the Ministry of Justice into all aspects of victim support."