Of course not. He had pink hair. The Joker has green. This is bogus.
His mother knew he was into something radical. She knew it was him right away and called police. My guess is she saw him get roped in by the "pay off my college loans" Occupy movement, and finally realized it wasn't going to happen for him. In fact, he dropped out of school, but still had all those loans to pay off.
The shooter went to USC Riverside on merit based scholarships, not student loans.