Talk:How the 'A' Stole Christmas/@comment-25337712-20141207233402/@comment-25547603-20141207234111

It's not just about the kidnapping imo. They have more than one reason to doubt about Alison. http://pretty-little-liars.wikia.com/wiki/How_the_%27A%27_Stole_Christmas#comm-452982

Anyway, trusting Mona is not the reason why they believed Ali is A. They already thought that. But yeah, it was stupid trusting her even if she helped them (at least this is what it seems) before dying.