Yes, there are time limits as to how long someone can be detained without being charged. Typically 48 hours.One thing I have always wondered is why when somebody asks for a lawyer do they not put suspect in cell and get a lawyer and then question them with a lawyer present, even if they choose to not answer questions LE still get to ask
In England you can have your solicitor (lawyer) when being questioned and they will ask questions and show suspect evidence even if they are refusing to answer "no comment" is the answer most give,
and all interrogations are recorded, nothing off the record, and one more question are there time limits in how long you can keep a suspect in police custody before they must be either charged or released? or as in England they have to go to magistrate (judge) to ask for more time
Sometimes hey seek a way to charge them with another crime in order to keep them incarcerated (for example, follow them around if they're not in jail, and watch for a traffic violation, etc.) They usually do this if the suspect is likely to flee or harm someone else. They were keeping an eye on Scott Peterson, and arrested him when it became clear he was about to try to get to Mexico, for example.