When a person goes missing, LE starts within a small circle. They look at the immediate family first, then they start widening the circle... other relatives, and close friends. In the very beginning, everyone is considered a suspect until LE can clear them. But a person does not have to be a suspect, officially, to be cleared. Ex: If there is a family member who lives in another city or state, LE will check them out just to verify they were not around when the person went missing. Technically, they are not a suspect, but LE still has to take steps to clear them.
My guess is that they are not going to name a suspect until they have enough evidence to arrest someone. Since Clint was the only other person at home, there is no way to verify his story, so officially he can't be cleared, but technically they don't believe he had anything to do with it.
Is this clear as mud?