The earliest case cited, Brown v. Mississippi (1936), holds that confessions extorted by force are inadmissible under the fourteenth amendment's requirement of due process. The two cases cited from 1990 are Illinois v. Perkins and Pennsylvania v. Muniz. Illinois v. Perkins holds that statements made to an undercover police officer posing as a fellow inmate are admissible as evidence even though Miranda warnings are not given. The court reasoned that Miranda warnings are not required when the suspect is unaware that he/she is speaking to a law enforcement officer and gives a voluntary statement. Pennsylvania v. Muniz determined whether various incriminating statements by a drunk-driving suspect, made while performing a series of sobriety tests, constitute testimonial responses to custodial interrogation for purposes of the self-incrimination clause of the fifth amendment. The Court determined that the officer's limited and focused inquiries were necessarily "attendent to" the legitimate police procedure and were not likely to be perceived as calling for any incriminating response. Dissenting opinions are included for some of the cases reviewed. Case footnotes.