Explications:
First, a boy named Victor saw Mark doing something in Annie's locker, and he found out that Annie lost her phone, so he accused Mark, and said that he was a thief. Victor told it to his friend Noah, then, Noah said that Mark stole Annie's phone to Alison. And finally,
Alison said to Mark : "Victor says you stole Annie's cellphone in her locker yesterday"
but Mark is Annie's Friend, he just put some books in her locker that day