Some soln.s are :
1.you can catch the student red-handed.
2.you can inform this to the librarian or your teacher.
3.you can observe what books she/he is tearing and one day you can give the book as a gift.
4.you can ask his/her parents to get the book.
5.you can form a group with your friends and discuss a solution.
6.you can advice the student .