On 5x13 I am convinced that it's not Ali or Cece who is wearing the black hoodie costume on the Dilaurentise's house, coz if it was A she could have done something worse than making Hanna lose consciousness. After 5x14 I am convinced that it is Mike Montogomery, the one holding the knife on 5x13 and the one who stole the laptop from Aria on 5x14. Maybe he is trying to solve the mystery of who really killed Mona and why she is killed. She broke in to the Dilaurentise's house to try and find proof too that Ali killed Mona and as for the laptop I think he thinks Mona knows something that will make Ali go after her and eventually kill her and he is trying to find out what it is.