Can my friend get in trouble for using a fake ID at the liquor store, after the fact?

Question Details:

A friend of mine used a fake id to purchase alcohol from a liquor store. The liquor store sold him the alcohol after asking for his id and they looked at it and let him leave. After he left, the liquor store called the police and reported his license plate saying that he was involved in selling alcohol to minors. The police then called his house. Can the police still charge him with something even though no one caught him or confronted him about it while he was using it? He wants to know if he should cooperate with the police and admit to anything? Important Notice