Pretty Little Liars Theory: Charles is Andrew’s brother
So here’s my theory.. I think Charles Dilaurentis IS Jason’s brother AND Andrew’s adoptive brother. Jessica Dilaurentis gave Charles up for adoption when he was younger (I don’t know why maybe because he had some mental issues and she didn’t want to take care of this huge responsability) and he was adopted by the Campbell family (Andrew’s family). Andrew is trying to protect the girls from his brother Charles because he found out about Charles’ bad intentions towards Ali and the liars but Andrew doesn’t want his brother to be in trouble with the police so he’s keeping this situation secret and he’s trying to protect the girls AND Charles. This is why Andrew starts acting like a creep with Aria and that’s why we saw him listening to Melissa and Mrs Hasting's call in 5x25. He’s just trying to keep an eye on them to make sure they’re not being threatened by Charles. I think Andrew is going to save the liars from the Dollhouse in 6x01 because he’ll find out where they are by looking through his brother’s stuff and at the end, Charles will be locked up in Radley.
HOWEVER, I don’t think Charles is Big A. I think he’s being manipulated by someone since he’s probably very easy to control because of his mental issues and his strong desire to get revenge on the Dilaurentis family because he feels betrayed and abandoned by all of them unlike Big A who wants revenge on Alison, the liars and their entire entourage for reasons who are still unknown. Charles Dilaurentis/Campbell is probably just another member in the Team A who does the dirty work for Big A.
