Hi Sarah

the rules are very clear: if you have been arrested even if the arrest did not lead to a conviction or if you have a criminal record then you are NOT eligible to use the visa waiver program and MUST apply for and be granted a visa. One of the major issues is that he has now left it very late to apply as he is going in December, so may not be able to get one in time. Up to now he has been able to get away with but to do so he has lied on the visa waiver form. Using the visa waiver is very convient but you have no right of appeal against the immigration officer's decision, and if he gets caught out then he will be deported on the next available flight. If you do a search on the forum for criminal records and convictions you will find that this is a topic that has come up several times. Your friend's decision is his to make but this is not a chance I would take.