The Fifth and Sixth Amendments to the US Constitution give persons accused of crimes the right to a lawyer, from the time he's "in custody" and then throughout almost all stages of the criminal trial. The idea here is to make sure that criminal trials are fair; that persons suspected of crimes don't get convicted and sent to jail unjustly and unnecessarily. The right to legal counsel helps to protect the rights and freedoms of those with little or no understanding of the law. It's one of the hallmarks of the US criminal justice system.
This right to counsel, however, can be waived or given up by someone suspected of or actually charged with committing a crime. As an added protection, however, to your basic right to legal counsel, your waiver has to be knowingly, intelligently and voluntarily made.
Fifth Amendment
The Fifth Amendment gives us many rights and protections, one of which is the right against self-incrimination. That is, in a criminal case, you can't be forced to be a witness against yourself. In the famous case of Miranda v. Arizona, the Supreme Court of the United States determined that this right to remain silent included the right to counsel. The Miranda case gave birth to the lines that we all hear when we're watching a TV show and the police arrest someone, called the Miranda rights:
- You have the right to remain silent. Anything you say can and will be used against you in a court of law
- You have the right to an attorney and to have that attorney present during any questioning
- If can't afford a lawyer, one will be appointed for you if you request one
This Fifth Amendment right to an attorney kicks in as soon as you're "in custody." Obviously, you're in custody when you've been arrested by the police, and this is when Fifth Amendment issues usually come up. However, you may be in custody and have the right to counsel, even though you haven't been arrested formally. For purposes of the Fifth Amendment, "in custody" means that a police officer or other law enforcement officially significantly restricts or limits your freedom or ability to move. For example, if an officer places someone in the back of his squad car and begins asking her questions about a crime that was committed in the area, it would reasonable for her to think that she's not free to get out of the car.
If the police question or "interrogate" someone who's in custody without first advising him of right to counsel (as well as the other Miranda rights), then anything he says to the police can't be used against him later in court. Once you've been told about your right to a lawyer and ask for one, the police must stop questioning you until your attorney is present.
Waiver
You may waive or give up your Fifth Amendment right to counsel, which lets the police talk to you and interrogate you, and anything you say can be used against you. Your waiver, though, has to be knowingly, intelligently and voluntarily made. That is, it can't be made by mistake or without your understanding of what it means, and it can't be coerced or forced out of you by the police. You have to fully understand your rights and the consequences of waiving them, and you have to waive them freely. So, the police can't ask a suspect who can't read to sign a piece of paper they call a statement of facts, but in reality is waiver of his Miranda rights. Likewise, the police can't use (or threaten to use) physical violence against you or your family to get you to waive your rights.
If you exercise your right to counsel and, later, voluntarily start or initiate a conversation with the police, then you've probably waived your right to counsel, and the police can use anything you say. On the other hand, if you make incriminating statements before you've been given your Miranda rights, and the police later give read you your rights, and then you again make incriminating statements, then your first statements generally can't be used, but the second ones may be.