Ernst Dumoulin, now 59, who has retrained as a church minister and remarried, described the night of Friday 13 October 1972 when he lulled his new bride, Helga Konrad,18, into a false sense of security as they sat on the edge of the 100ft-high cliffs at Salisbury Crags, near Arthur's Seat in Edinburgh.
He said: "It was the darkest night of my life. I held Helga in my arms and kissed her passionately. I wanted her to feel that I loved her above everything else. I spoke about how we would have a wonderful future filled with love and wealth. She believed me.
"We sat on the cliff and enjoyed the views for a while before I said: 'Let's go home'. I got up, put a hand on her shoulder and acted as though I had tripped up. I didn't want her to know I was a murderer.
"I pulled her and her body fell, and after that everything was quiet."
At his trial, Dumoulin confessed to attempting to defraud insurance companies, but lodged a special defence of self-defence, saying Helga had tried to push him.
He served 16 years in Saughton Prison, before spending five years studying theology.
Earlier this week, Dumoulin told a reporter from Bild, the German newspaper, who tracked him to the small town in Germany where he works as a Protestant minister, that he found God in jail.