The police can pretty much do what ever they want, but if they trample your rights, they will be chastised when it goes to court and everything is thrown out due to misconduct. Never take a plea, let your lawyer do his job, usually in the final moments right before or right after hearings have started the state backs down and drops the charges. Seen it happen a lot. Also seen most people take a plea thinking they are keeping themselves from doing real time. Never consent to a search, and if a police person ever asks if you "Understand" something,always tell them them that you DO NOT understand, even after they have explained it a million times, you NEVER understand. By agreeing with them that you understand something is the same as consenting.