My friend is a convicted felon but his dna was never taken before he left the country. He is a green card holder and he is been out for 11 months and wants to come back. Would they find out at the port of entry about his conviction since there was no booking/dna sample after the sentence before he travelled. There was no jail term and he is currently on summary probation for 3 years. He is actually coming to complete his booking process because there has been several notices for him to make an appointment for the dna sample. He has not been able to come back due to serious medical condition which did not permit him safe flying for more than 7 hours. Would there be any problem for him? Or would they know about his conviction just by using his name? Please advice, thanks.

Name and fingerprints tell all... don't waste time and $$.