A mother has begged her daughter's killer to solve the mystery still surrounding her death.
Speaking to the Press Association, Ramona Muller told of the torture she still endures every day while "so many questions" remain unanswered after her daughter Janet's death in Sussex three years ago.
Court and inquest proceedings heard the German student, who was studying in the UK, had been admitted to a mental health hospital and escaped by climbing over a wall.
Her body was found the next day in a burnt-out car which had been dumped near Crawley. Christopher Jeffrey-Shaw was convicted and jailed of her manslaughter.
So far, there has been no evidence to suggest the pair previously met.
The 47-year-old, who lives in Berlin, said: "We still don't know what happened in the last 12 hours of her life.
"You got to bed every night thinking 'What happened?' and 'Why can't we find the answers?'
"We are still going to try and find a way.
"We hope Jeffrey-Shaw will speak out because he is the only one who knows what happened.
Mrs Muller has not spoken publicly of her ordeal until this week, telling of her heartbreak when she arrived in England on her birthday to discover her daughter was dead.
She said: "Janet's body was found on March 13. I did not know the police had found her body until I arrived in England on March 18 - my birthday - and my other daughter told me. The police didn't inform me.
"I thought I would wait until the time was right to speak about everything. I didn't want to interrupt any investigations. It's right now to say how we feel.
"It will not bring Janet back. But it would have been her intention to ensure other patients are safe, treated with respect and are not forgotten.
"We still hope we can force change."