I <3 Memes said:You would be surprised what you will admit to after 10 straight hours of questioning. Eventually your brain just wants the questioning to stop.
Not certain about this, but I think some states have laws in place that limit how long an interrogation can go on before any information gained from it, or any confession, is considered inadmissible. Essentially puts a time limit on the interrogation. I think its around 8 hours.
But to quote from my bad memory Frank Pembleton from the loved, yet dead, TV show 'Homicide: Life on the Streets':
"Did you miss the sign that said 'Homicide Division' when you walked in here? Why would you open your mouth to say anything? There are people out there trained in the law whose sole job is to protect your rights, and if you can't afford one, one will be provided at no cost."
If cops want to talk to me about some murder than happened, they get a few informal informational questions. If it goes past that or we go down to the station, 1-800-Rentasuit.
EDIT: Supreme Court Ruling on federal crimes:
http://criminal.lawyers.com/Speaking-Up-for-the-Right-to-Remain-Silent.html
The Court held that a person charged with a federal crime can't be held and questioned more than six hours without being brought before a federal Magistrate Judge.
Limited to 6 hours, but that's not to say state courts won't follow. And this ruling was in April 2009, so its quite recent.