Barry surely had full confidence he could control Suzanne. Naturally HE wouldn't call it controlling but it is what it is. He controlled the money, the real estate, the family. What she wore, what she ate, how she cleaned.
We come to find out that Suzanne had a lovely family who loved her very much. He boxed them out.
The time for Suzanne to leave might've been 2018. If he would've let her. But she was torn. He makes threats. Suddenly she needed him for health coverage, with a new diagnosis. One daughter was still young, one was moving away.
Barry must've begged, threatened, cajoled, love bombed and guilted her mightily. Borrowed money from Gene, used Suzanne's inheritance to buy PP. (Indiana hadn't sold, was rented almost like a contract for deed, due 6/2020 or so.)
Once in Colorado it was WORSE than before. Suzanne was trying to white knuckle it until the Second's graduation
She actually believed there was a path forward, that he would let her go.
I think Suzanne saw the pending sale of the Indiana home as the opportunity to recover her inheritance, divorce, and live locally for that senior year.
Barry didn't see it that way. And have people know he couldn't control/satisfy his woman? Settle up accounts. Half and half, with Suzanne recovering her inheritance*, to boot? Not gonna happen. He put her off for months, years by refusing to talk about it, likely forcing her to recite all he'd done for her.
*Her inheritance, comingled so divorce court might consider it joint, but Barry acquired it then fraudulently because he clearly represented and understood it was her and all hers -- and made promises to give it back -- just didn't. And wasn't going to.
I still think something happened on the Wednesday that was too illuminating for Suzanne to ignore anymore.
Barry decided to stop her before she could take action.
If somehow she'd lived through Mother's Day and closed on the Indiana house, sadly she'd have learned he wasn't going to give her her money back, not then either. Not ever.
Divorce was never going to be an option with Barry. Not when he had tranquilizer darts lying around.
Why? What made him so special? Why couldn't he just divorce like normal people do every day?
Ego.
JMO