He's not
No Ian is the killer and Mona is A.
Not even close the killer is Ian.
he is the killer. but he raped her first.
Because A makes it seem that Ian is Ali's killer
He is or is not, i don't think he is in my opinion, i think he is the killer but, not A.
because he was with her at the kissing rock the night that she disappeared
No
A
No.
no
No
People suspect it is Ian but its not completely revealed because the only people who knew, Mona and Ian are both dead.