I'm curious why you wanna report to your superiors instead of letting him get caught red handed. He's coming in late and going AWOL on his cognizance.
There are better ways of doing it without you reporting it. Both of you ORD already or haven't?
If not, what you can do is create a trap, something simple, for example, if this guy is already coming late, then that means he's shirking on his responsibilites, maybe a missing signature here, not turning up for guard duty, etc. Find something that will make a superior officer call him and to report immediately to him. If he's not around to answer the officer, or if he answers but takes a long time to report, then he's in trouble already. And he's non the wiser that you started it.
Don't put your name on anything unnecessarily.