Can the non custodial parent be in trouble for not filing his taxes just to avoid paying child support?

Hi quick details here. My ex, who has never had anything to do with his daughter, owes back child support. She is 11 yr old and last year 08 my husband (who my daughter only knows as dad) adopted her. However my ex still owes child support for the 10 yrs before that. He is responsible for everything up until the adoption was final this I know. I know they will take his taxes because he owes child support problem is he doesn't file. As far as I know he has not filed since 04. I live in Illinois and last year they sent notices to anyone owing back support saying that if they didn't pay their support for so many days ( I think 90 days) they will take your license yeah that didn't happen. Its been much longer than 90 days since he last paid support. But anyway back to the taxes. I am pretty sure that he isn't filing because it is just a waste of time for him he has to pay up front to have them done and he has to spend his time preparing them when he isn't going to get anything back. If he did get a refund I would get it so why should he file right?? That is what I am sure he is thinking. Can he get in trouble or is there something I can do to make sure he files? I am pretty sure its against the law not to file even if you are due a refund am I right? Especially if you are not filing because you owe child support.