What can we do if my husband is being falsely accused?

My husband and I were staying with a friend of ours and we were kicked out due to miscommunication, and now two months later we find out he is being accused of "touching" our friends 7 year old daughter and taht a CPS case was opened. A detective called after a month has gone by to say he needs him to come in to get his side of the story so he can close the case. We both know he NEVER would do such a thing as we have a child ourselves and we do know that our friends daughter was having issues like this related to another child at school. Due to the unfriendly way that we parted ways with our friend, we think this is some sort of retalitaion. Do we need to be concerned and hire a lawyer when he goes in or be worried he may get falsely arrested?