Since 1966, Miranda v. Arizona has served as the touchstone for the exploration of the scope of the privilege to be free from self-incrimination during a period of custodial interrogation. The Constitution's Fifth Amendment guarantees to all people the privilege to be free from self-incrimination. In BERGHUIS, v. THOMPKINS, decided on June 1, 2010, the Supreme Court decided that it was up to the defendant to assert his Miranda rights after being advised of them. No assertion, no violation of Miranda.
The Court in Miranda created right to counsel procedural safeguards to adequately ensure that the accused know their rights and that the police honor them. The Miranda Court recognized that "[a]n individual swept from ... familiar surroundings into police custody, surrounded by antagonistic forces, and subjected to ... techniques of persuasion ... cannot be otherwise than under compulsion to speak."
To effectively safeguard a suspects' privileges under the Fifth Amendment, the Miranda rights create the obligation to clarify and should prohibit law enforcement officers from badgering suspects into converting their previously ambiguous request for counsel into a clear waiver of the right to counsel.
Once your are in custody, say nothing other than to ask for a lawyer.