Replying to OWI/DUI Laws....Help

I come to NS asking for any help at all. I have been looking everywhere and haven't been able to find what I was looking for.

Here's the situation: My little brother moved out to Denver about a year ago. A month or so ago, he was arrested after blowing a .06 BAC and charged with a DWAI. Being from Iowa, where the law is .08 he was rather surprised.

He was charged in 2006, in Iowa, with a OWI/DUI 1st offense. He received a deferred judgment.

He recently had his court appearance in Denver. Met with the DA, had a plea deal ready to go, went into court and the judge asked him if he had ever been charged with a prior OWI/DUI. He said yes, the judge threw the deal out and wanted to charge him with a 2nd offense. He informed her that it was deferred, she didn't care. Has an upcoming court date in May.

Anybody know if the deferred judgment can hurt him in this case? Can they charge him with a 2nd offense?

He has talked to a lawyer, the guy wants 6 grand, which he may end up doing, but we are just curious about what to do in this situation. Any help/knowledge would be greatly appreciated. Thanks and sorry for the wall of text.