I got admitted despite a DUI from less than 3 years ago. Check with the state where you want to go to school: California only lets background checks go back 7 years, but the school still let me in because my "clearance" was up 3 years before the semester actually started. They told us in the information session that the primary
offenses they frown upon are fraud and abuse. They also told me that, if the DUI was less than a couple of months ago, it "might" matter. I did my own background check (from a different site than the school required) to see exactly what showed up, and told the school what I had BEFORE I turned in the official background check that they required (I was afraid that an old DUI from 10 years ago would show up).
don't worry about DUI's; I didn't even have to get formal court papers to show them. The school just "reminds" students that the "State Board" might
not let you take the NCLEX but, again, they mainly worry about recent felony-type stuff.