I'd also add that the vitriol aimed at you by some posters is just awful and probably contributes to the low rates of women leaving men such as this. I always feel the need to post on these situations as I hope I can reach at least one person.
I had no idea - I am an intelligent, educated, professional type. I did things "right". I knew him years, we waited years to get married, have kids etc... And I was totally blindsided.
When your world implodes and the police turn up at your door, you do not want to believe it. How could someone you know and love do this, surely it is a mistake. You are given limited information by the police as you are not a direct victim, and the men will inevitably minimise their behaviour. You will want to believe them - otherwise how could you get it so wrong ? It will take years to come to court and during that time, you will be told little to nothing. If they plead guilty, limited information comes out at court (only enough for sentencing) so you still don't know the full truth. Maybe (probably) you never will.
You are told by the police to keep it quiet because they are worried about consequences from the public if it becomes known. So you are further isolated. You are handed leaflets from organisations that help these offenders - but they are focused on how to move forward and forgive, because ultimately they are there to help the offender and not you. So another pressure to stay and forgive.
Then there is the choice to leave - find somewhere new to live, maybe you have no job, try to manage any children alone possibly with limited or no family support. All more pressure on you. And that is without the financial pressure from losing an income (and there is likely to be little/no child support as they will lose their job).
However, you are not a direct victim or the offender, so there is no funding or counselling available for you if you do chose to leave - only if you stay. I am under no illusions that my choices would have been so much harder if I did not have my amazing family support and a decent job.
Then there is the guilt - how could you not have seen it ? What about the poor victim ? What will you tell your own children now that they father has suddenly been removed from their lives ? What about when their friends find out what he has done ? What about your kids friends who have been in your home ? You feel you are the last person who deserves sympathy.
And then you get comments like that from @DazedAndConfused321, who should be ashamed of themselves. But, it is easier for people to blame you and assume you knew or are complicit. They wouldn't ever fall for someone like that, so would never have such complicated feelings arising from discovering what you knew was a lie. It is easier to believe you knew, because the alternative is accepting the fact that these people are master manipulators hiding in plain sight and the person they know and possibly share their lives with could be so convincing as to have tricked them too. It is such an awful thought that people do not want to accept it. I knew my ex for nearly 20 years and I never saw it coming. Neither did anyone who knew him.