I took the following passage from the Policeman's Blog (UK). You will see that a man is imprisoned in a cell for hours, because he had an argument with his wife on the phone, ...
I recently spent five hours in custody, dealing with a suspect whose wife had alleged he had made some abusive telephone calls, that’s almost a whole shift. It’s incredibly frustrating when you know there’s no evidence against a suspect and you know there’s never going to be any, and that any case that’s put to him will be dismissed almost immediately, but because police officers have to be seen to be doing everything possible, people (officers, suspects and lawyers) spend hours in custody, just waiting. At the same time, because you have a prisoner in custody you cannot leave the police station to do any work on other cases, or go out on patrol: you just wait.