Alternatively, the accused could both do a confession in front of a judge 4 separate times but they can retract this confession at any time and avoid any punishment.
Your Islamophobia is showing a bit too much.
If they choose to get together and through the democratic process of whatever county, city, or state they live in decide to implement laws that they believe are beneficial to them then the democratic process is working as its intended.
Islam, as written in the Quran and the authentic ahadith, will never force anyone, including non-Muslims, to practice any part of the Muslim faith.
Sharia law actually has some good ideas in it. I think we should investigate Islamic banking and see if any of it would improve our economies. Because charging interest is forbidden in Islam, many of them do mortgages as a rent to own system instead, which leaves the bank on the hook if the house value crashes, instead of the buyer, so banks don't give out stupidly big mortgages that you might not want to pay back.