Her remains were discovered in a basement in Gloucester more than 20 years later.
Ms Partington told the BBC: ‘To me Lucy’s life was sacred and I needed to reclaim her as a person, as my sister, from what happened’ (Picture: PA)Marian Partington, her elder sister, spoke to a BBC Inside Out West documentary broadcast 25 years after the horrific acts of the Wests were discovered.
The couple tortured, raped and murdered an unknown number of women over a 20-year period, between 1967 and 1987.
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Fred West was charged with 12 murders but took his own life in a Birmingham prison before his trial.
Rose West was convicted of 10 murders in November 1995 and is serving a life sentence.
Ms Partington told the BBC: ‘To me Lucy’s life was sacred and I needed to reclaim her as a person, as my sister, from what happened.
‘Then it came to me that the only way out of this was to move towards forgiveness, but I had no idea what that could mean, or how that could be possible, but I made a vow to try and forgive the Wests.
‘The first thing I experienced was murderous rage, so I realised that this is the beginning of my journey towards forgiveness.
Marian Partington, her elder sister, spoke to a BBC Inside Out West documentary broadcast 25 years after the horrific acts of the Wests were discovered (Picture: PA)
Lucy Partington, 21, who studied at the University of Exeter, vanished on December 27 in 1973 (Picture: PA)
Serial killers Fred and Rosemary West (Picture: PA)‘I have details about Rosemary West’s childhood – the violence in the family, the neglect and the abuse, and [I have tried] to imagine what would it be like to grow up with very little love.
‘I can’t see how there can be any cruel actions that haven’t got a root in something else, something that has happened in somebody’s life.
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‘But then people will always say that’s not an excuse.
‘And I say very clearly I don’t forgive the Wests for what they did, but I forgive them as people for whom there didn’t seem to be another way of living.’
Ms Partington has kept a small woollen bag her younger sister made her aged eight.
‘She gave it to me as a gesture of love and when I look at it I still remember that,’ she said.
‘At the memorial service one of her friends described her as ‘indelible’, that she made a mark on people that she touched people’s lives.’
The documentary will air on BBC One West at 7.30pm on Monday.