Who is Charles DiLaurentis?

Hey guys welcome to my first post, as you can see im pll Obsessed ! <3 So if you haven't caught up with pll, Read no more:) Okay so in The 5B Finale, We found out that charles is -A Okay so  i have a theorie, what if The girls did something to charles DiLaurentis ''That night'' But can remember because they were drugged by Ali? Do you think Jason is Apart of the -A Team???. Who is Charles DiLaurentis?