I'm sorry you went through such a frightening experience, but glad nothing worse happened to you. Chalk this up as a learning experience.

A social group where "spouses are not included" does not sound like a wholesome gathering. I could see, if it were all women. But mixing single women with married men is a set-up for trouble. As a single woman, you are not betraying the trust of a partner. But members like this guy are, just by gravitating toward this group. I think you would do well to find a different way to network and build friendships, other than by being a part of this strange association.

The police are going to have zero interest in investigating your experience. A doctor is going to have zero interest in prescribing a drug screening blood test for you. The man's wife is going to have zero interest in hearing from you.

You put yourself in a dangerous situation. It was probably wise of you to avoid antagonizing this guy, while you were more or less under his control. That was your survival instinct kicking in. You are only lucky you were not the victim of something way worse than groping. This man is not safe to be around. Unfortunately, there are a lot of men like that, who will test a woman's boundaries and see how far they can get. The police can't possibly start compiling dossiers on every one of them. Even if they listened to you politely, they'ld be laughing at you, the minute you left them. No, this is not a laughing matter at all. It is best thought of as a lesson.