I have been a police officer for many years. I am amazed at how many officers do not fully understand when a person has to be advised of his/her Miranda warnings. I feel that this should be a fundamental part of the law that all officers should completely understand.
What are Miranda warnings? The United States Supreme Court in the case of Miranda v. Arizona, 384 U.S. 436 (1966), established an irrebuttable presumption that a statement is involuntary if made during a custodial interrogation without the "Miranda Warnings" given. Basically, this means that if a person is in custody and questioned without being given the warnings, everything the person says will be inadmissible in court. Miranda warnings are a list of warnings that the officer must advise, either in writing or verbally, to a person before questioning. There is no difference in the application of the Miranda warnings when the crime is either a misdemeanor or felony.  The following is a typical Miranda warnings advisory:
For the purposes of the Miranda warnings advisory, "custody" is an arrest or when freedom is significantly deprived to be equivalent to an arrest. To clarify this further, "custody" will include a person that is under arrest for a crime, a person handcuffed for officer safety, a person placed in the back of the police car, or any other custody type treatment. "Interrogation" is the formal and systematic questioning of a person to elicit incriminating statements of his/her criminal activity.
Because many police officers do not fully understand the reasoning behind the Miranda ruling, defense attorneys easily confuse them in court over this subject. Has a defense attorney ever grilled you in court over not reading the Miranda warnings to his client when you questioned him on a traffic stop? Have you ever heard the question, "He was seized and not free to go, so why did you not Mirandize him?" Well, I am about to explain why you don't have to Mirandize him. Both custodial treatment and interrogation must occur for the Miranda warnings to apply. A person can be questioned all day, as long as the person is not being subjected to custodial treatment. A person can voluntarily come to the station, be advised that he will be free to go anytime during or after questioning, and be questioned about a crime he may have committed without being warned.  A person can also be subjected to "curbside questioning" without being given the warnings. A routine traffic stop does not rise to the level of "in custody" treatment under the Miranda ruling. A person in the stopped vehicle can be questioned without being given the warnings. For example: a drunk driver stopped by an officer can be questioned about how much he had to drink, what he was drinking, what bar he came from, etc. without the warnings as long was it was done before the person was arrested.  Another example of this involves a "Terry" stop.  A person on foot that is stopped by an officer for reasonable suspicion of a crime can also be questioned without the Miranda warnings. Again, the person must not be subjected to custodial treatment; otherwise the Miranda warnings must be given.
What if you make a mistake and obtain an incriminating statement without reading the person the Miranda warnings? The United States Supreme Court made the following statement that answers this question: "Absent deliberate coercion or improper tactics in obtaining an unwarned statement, a careful and thorough administration of Miranda warnings cures the condition that rendered the unwarned statement inadmissible".  So, all you have to do is read him the Miranda warnings and question him again. Any deliberate or improper tactics, however, will bar any admissions. The Miranda warnings cannot overcome the taint of an illegal arrest. 
Anytime a person clearly invokes the rights under the Miranda warnings, all questioning must stop. The only time questioning can resume, is if the person reinitiates the questioning.  Many officers, either by department requirements, common practice, or because that is the way it is done on TV, read suspects their Miranda warnings upon arrest. This is a bad practice to have. The best way is to read the suspect the warnings at the time of questioning, and not before. This will help prevent any confusion and the elimination of statements. Let's say that I arrest someone for armed robbery. I then read him the Miranda warnings, although he will be questioned not by me, but by detectives later on. He requests counsel. I do not convey this to the detectives. The detectives then read him his rights. He makes several admissions of guilt. Everything he says will be inadmissible in court.  If you are not going to question a suspect, don't give the Miranda warnings.
Over the last few years there has been several updates to the Miranda Warnings requirements. The first involves the case of Maryland v. Shatzer. The court established a new rule for Miranda Warnings. Once a person has been read the Miranda Warnings, the person is now in Miranda Custody. A police officer must wait a period of time after the person is released from Miranda Custody before the person can be questioned again. The Court determined that 14 days is a reasonable time for the person to get re-acclimated to his normal life, consult with friends and counsel, and shake off any residual coercive effects of prior custody.
When a person being questioned under Miranda remains silent, the police officer does not need to consider this an invocation of the person's right to remain silent. The person must make an unambiguous assertion of his rights under Miranda. Until the person states clearly that he is invoking his Miranda rights, the officer can continue to question him (Berghuis v. Thompkins). The Supreme Court further held that a signed waiver of the Miranda rights is also not required. The actions and words of the suspect are sufficient to infer a waiver.
Bobby v. Dixon case held that a person cannot invoke his Miranda Rights anticipatorily in situations other than while in custodial interrogation. If a police officer reads a person the Miranda Warnings before being taken into custody, in this case 5 days before, the invocation of rights by the person can be disregarded when the Miranda Warnings are re-read to him after the actual arrest. This case also means that a person who is about to be or just been arrested cannot just blurt out that he will not talk to the police without his attorney. The person has to be taken into custody and the police have to read the Miranda Rights before the person can invoke his rights.
J. D. B. v. North Carolina case held that the age of a juvenile now has to be considered when determining if the child is in custody for the Miranda Warnings to apply. Being held in a Principal's office and questioned by police may be a situation based on the age and maturity of the juvenile where he may be "in custody" requiring the Miranda Warnings be read.
The United States Supreme Court established the Miranda warnings as a remedy to police officer interrogation abuses under the Fifth Amendment of the United States Constitution, which deals with self-incrimination.  Remember, you must Mirandize when the person is in custody and questioned. If you know your job, do it legally, and do it right, you will be a better cop for your agency and your community.
 Amendment V of the United States Constitution-No person .shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law.