Miranda rights are informing an individual of their right to remain silent and retain legal counsel. That is the crux of the Miranda warning. What this rule says is that any time the authorities detain a person, that person is subject to detention as part of the arrest process. If the government, police officer or prosecutor is going to interrogate this person, they have to read them their rights if the government wants to use any statements or any evidence derived from these statements against the accused. According to MirandaWarning, if the government fails to advise the accused of this, then any statements the individual gives or the evidence that is the fruit of those statements cannot be used against the individual.
So in this most basic form, do officers making arrests have to read someone their Miranda rights? No. They just simply cannot interrogate and then use those statements against the individual. If they do interrogate and receive information, that information will generally be excluded and cannot be used against them because they were not informed of their rights.
But are there exceptions to this rule? Are there situations where an arresting officer can interrogate without reading the Miranda rights and the information is still susceptible or capable of being used in a court of law? According to FindLaw, there are exceptions. One is where the police arrest an individual but they do not interrogate them. The individual simply just makes spontaneous statements or unsolicited statements in this situation, not pursuant to an interrogation. Another instance is when an individual makes statements before the police arrest them.