Question 1959) - How do the courts establish Zina to have been committed?

A: It is established through evidence or confession.
Evidence: Four witnesses testify that a man or a woman committed Zina. After they testify the court will question them, "what is Zina? How was is done? Where? When? With who?? Once they have clarified that and said, "we saw him penetrating her vagina just as an antimony-stick enters the antimony bottle," the judge will investigate the piety and justice of the witnesses. If they fulfil the requirements of justice in secret and open, he will rute according to their Arsh and inflict the Hadd. If their number falls below four or one of them is established as Fasiq [open sinner] then all the witnesses will be inflicted with the Hadd of slander.
confession: A sane adult confesses four times to having committed Zina. The confessions will be four separate gatherings. Each time he confesses the judge will refuse him. It is recommended for the judge to refuse him in these words, "perhaps you just touched or kissed her.? when the person completes his confession as mentioned, the judge will ask him "what is Zina? How was is done? where? with who?? Once he does that the Hadd becomes mandatory.

~ al-Quduri ~