A Miranda warning is a list of rights that people in the United States have when they are being questioned by the police or arrested.  These rights are called Miranda rights.  Because of a United States Supreme Court decision in a case called Miranda v. Arizona, , the police have to give a person this list of rights before they start questioning them.

One goal of the Miranda warning is to make sure that suspects' rights under the Fifth and Sixth Amendments to the Constitution are protected.  Another goal is to make sure suspects know about their rights, and know that they can use them.

Background

Crime

In Miranda v. Arizona, a man named Ernesto Miranda confessed to raping and murdering a 17-year-old girl.  Miranda was convicted and sent to prison.  However, he and his lawyers appealed his conviction all the way to the Supreme Court.  They argued that Miranda's confession should not have been used as evidence because:
 The police never told him he had the right to a lawyer
 The police never told him he had "the right to remain silent" (the right to refuse to answer questions).  This is called the "right against self-incrimination" (the right not to say anything that will prove you committed a crime).  It is protected in the Fifth Amendment.

Supreme Court ruling

The Sixth Amendment protects the right to a lawyer, but the Supreme Court had also just recently made two landmark decisions about this right.  In 1963, the Court ruled in Gideon v. Wainwright, , that anyone being tried for a crime had the right to a lawyer.  If the person could not pay for a lawyer, the state had to assign them a free lawyer.  The next year, the Court ruled in another landmark case called Escobedo v. Illinois, , that anyone suspected of a crime had the right to have a lawyer with them while the police questioned them.

The Supreme Court decided the police got Miranda's confession by ignoring his rights, and they threw out Miranda's conviction.  (Miranda was re-tried, and even without the confession as evidence, he was convicted again.)

The Court also ruled that police have to make sure suspects know and understand their rights before being interrogated.  Specifically, police have to give a "Miranda warning" that tells suspects they have these rights:
 The right to refuse to answer any questions ("the right to remain silent")
 The right to have a lawyer (including a public defender  a free lawyer, if the suspect cannot pay for a lawyer)

Basic Miranda warning
An example of a Miranda warning often used in the United States is:

Many people from all over the world know these words from television and think of this as "the Miranda warning."  However, there is no one version of the Miranda warning.  Different people, police departments, and states use different words.  The Supreme Court has said the words can change, as long as the four basic parts of the warning are there.  In Simple English, they are:
 The suspect has the "right to remain silent."  They do not have to say anything and can refuse to answer any questions.
 Anything the suspect says that is related to a crime can be used as evidence in court to prove their guilt.
 The suspect has the right to have a lawyer.
 If the suspect cannot pay for a lawyer, they still have the right to a lawyer.  The court will assign a free lawyer for them.

Different versions
There are at least 945 different versions of the Miranda warning just in English. Some versions warn non-citizens of their right to consult their nation's consulate before questioning continues.  Some try to make the warning easier for juveniles or people with learning disabilities, intellectual disabilities, or mental illnesses to understand. Some may ask the suspect to confirm that he or she understands the warning. However, studies have shown that in fact, people in these groups often have even more trouble understanding the 'simpler' versions.

The Miranda warning has also had to be translated into many different languages.  Many different police departments carry cards that show the warning in different languages.  Others use translators to give the warning.

When it is used
The law says the police have to give a suspect a Miranda warning before they start questioning them.  If they do not, and the suspect gives a confession, that confession could later be thrown out in court.  This means a court could rule that the confession cannot be used as evidence in a trial.  A confession can also be thrown out if the police gave a Miranda warning, but gave it the wrong way, or did not make sure the suspect understood it.  (This is discussed more in the "Problems" section.)

For Miranda rights to be an issue at a trial, six things must be true:
 The suspect gave the police evidence during an interrogation
 This evidence was information  something the suspect said to police (not a thing, like clothes or a blood sample)
 The suspect gave this evidence while in police custody (under arrest, or not allowed to leave the police)
 The suspect gave this evidence during a police interrogation
 The suspect knew the people questioning him were law enforcement officers
 The state uses the suspect's confession during a criminal trial

If these six things are true, then the prosecution has to prove that:
 The suspect was given a Miranda warning;
 The suspect understood his Miranda rights; and 
 The suspect decided not to use his Miranda rights.

If the prosecution cannot prove each of these things, the confession can be thrown out.

Problems with the Miranda warning

Complexity
Studies of many different versions of the Miranda warning have shown that most of them are complex.  The more complex the Miranda warning is, the harder it is to understand.

For example, one study from 2008 looked at how complex the sentences were in the average Miranda warning.  They found a "sentence complexity" score of 48.96  which meant the sentences were as complicated as the instructions on United States tax forms.  In some of the warnings, the information about Miranda rights was more complex than a college-level accounting textbook.

Some areas have "simplified" versions of the Miranda warning.  However, researchers have found that these versions are not always easier to understand.  A person would need high school-level reading and language skills to understand some of them.

In a study of 560 different English versions of the Miranda warning, researchers found that a person would need 7th-grade reading skills to understand the simplest versions.  To understand the most complicated Miranda warnings, a person would need a doctoral-level education (the highest level of education you can get at a university).

Misunderstanding
According to the American Psychological Association, people are so used to hearing the Miranda warning on television that they think they understand their rights.  However, a 2011 study by Richard Rogers says that many people do not understand their Miranda rights, or have wrong beliefs about them.  For example, Rogers found that 31% of defendants waiting for trials in Texas and Oklahoma did not understand their right to remain silent.  They believed that if they did not answer questions, the court would use that as evidence of their guilt.  Rogers also found that 36% of college students believed the same thing.

Other studies have shown that most juveniles (children and teenagers)  and many adults  do not understand their rights well enough to decide when to use them and when to waive them (not use them).  For example, in one study, a researcher asked juveniles and adults to repeat back the Miranda warning in their own words.  The researcher also asked them to define six of the most important words in the Miranda warning, like "consult," "appoint," and "attorney."  Finally, the researcher tested whether they could understand different versions of the Miranda warning.  He found:
 Only one out of five juveniles (20.9%) understood all four parts of a Miranda warning.  Just over two out of five adults did (42.3%)
 Over half of juveniles (55.3%) and almost one quarter of the adults (23.5%) did not understand at least one of the four parts of the warning
 Juveniles who did not understand their rights were more likely to waive them (not use them)
 Poorer children were most likely to waive their rights

Juveniles
No Supreme Court ruling or federal law has ever said that children must have a parent or lawyer with them while being questioned.  About 12 states have chosen to add extra protections for juveniles in their states, like not letting juveniles waive their Miranda rights without a parent or guardian there.  However, most states have not done this.  This means that in most states, juveniles can waive their rights on their own.

A famous study done by Richard Rogers and others in 2008 looked at Miranda warnings that were meant to be simplified versions for juveniles.  He found that these warnings were longer than the non-simplified versions; some had as many as 526 words.  Understanding them also required higher reading levels and abilities than the adult versions.

Another study, done in 2013, found that 16- and 17-year-olds charged with a felony almost always waived their Miranda rights.  They waived their rights 93% of the time, while adults waived their rights 80% of the time.  Especially when juveniles waive their rights and agree to talk to police without a lawyer, they are much more likely to confess to something they did not actually do.  Looking at people who were proven to be innocent, studies found that one-third to two-fifths of untrue confessions came from juveniles.  Police got almost 7 out of every 10 of these false confessions from children ages 15 and under.

A report from the American Bar Association suggests this version of the Miranda warning for juveniles:

Languages
Translating the Miranda warning into other languages brings up special problems.  There have been many cases where suspects' confessions have been challenged and thrown out in court because of problems giving the Miranda warning in other languages.  For example, since 1993, there have been lawsuits about:
 Suspects who speak Arabic, Cantonese, Dinka, Korean, Mandarin Chinese, Somali, and Spanish being given Miranda warnings in English
 Suspects who speak Spanish and Brazilian Portuguese being given written Miranda warnings that were not translated correctly
 Police using translators who made mistakes, did not know how to translate legal words, or just did not speak the suspect's language very well
 Police using translators who did not speak the suspect's language at all

The Miranda warning is also difficult to translate into some languages.  Not all languages have words for the same ideas as English.  For example, American Sign Language has no signs for legal words like "rights."

Related pages
 Miranda v. Arizona
 Fifth Amendment to the United States Constitution (protects the right to remain silent)
 Sixth Amendment to the United States Constitution (protects the right to a lawyer)
 Gideon v. Wainwright (protects the right to have a lawyer for any criminal charge, free if needed)
 Escobedo v. Illinois (protects the right to have a lawyer while being questioned by police)

Notes

References

Other websites
 Know Your Rights: Simple English brochures from the American Civil Liberties Union about your Miranda rights
 Know Your Rights When Being Questioned by Law Enforcement
 Know Your Rights As a Juvenile 
 Deaf Rights: What to Do if You Are Dealing with the Police  (starring Marlee Matlin)
 Information for Non-Citizens

United States law