Can somebody explain this play?

I'm a little bit confused.

AA raise good preflop. Flop 34K Rainbow. Deep stacks, blinds 100-200

BB checks I bet, then he check raises me all in. Flips 109.

Turn 10 River 10.

Not the best way to get sucked out, but I still don't understand what was happening in his head when he check raised me all in. I am loose enough, but I would not be able to pull some stunt like that ;)