Editing Miranda v. Arizona (section)

===Miranda warning===
{{main|Miranda warning}}
After the ''Miranda'' decision, the nation's police departments were required to inform arrested persons or suspects of their rights under the ruling prior to custodial interrogation or their answers would not be admissible in court. Such information is called a [[Miranda warning]]. Since it is usually required that the suspects be asked if they understand their rights, courts have also ruled that any subsequent waiver of Miranda rights must be knowing, intelligent, and voluntary.<ref>See, e.g., {{cite web|title=''Colorado v. Spring'', 479 U.S. 564, 856-57 (1987)|url=https://scholar.google.com/scholar_case?case=15310909188377217773|website=Google Scholar|access-date=18 March 2018}}</ref>

Many American police departments have pre-printed Miranda waiver forms that a suspect must sign and date (after hearing and reading the warnings again) if an interrogation is to occur.<ref>{{cite journal|last1=Edwards|first1=H. Lynn|title=The Effects of Miranda on the Work of the Federal Bureau of Investigation|journal=American Criminal Law Quarterly|date=1966|volume=159|pages=160–161|url=http://heinonline.org/HOL/LandingPage?handle=hein.journals/amcrimlr5&div=37&id=&page=|access-date=18 March 2018}}</ref><ref>{{cite web|title=Miranda Waiver|url=https://www.una.edu/police/docs/forms/miranda.pdf|website=University Police Department|publisher=University of North Alabama|access-date=18 March 2018}}</ref>

Data from the [[Uniform Crime Reports|FBI Uniform Crime Reports]] show a sharp reduction in the [[clearance rate]] of violent and property crimes after ''Miranda''.<ref>{{cite web|url=http://www.ncpa.org/pub/st218?pg=4 |title=Handcuffing the Cops: Miranda's Harmful Effects on Law Enforcement {{!}} NCPA |date=2015-05-18 |access-date=2016-09-28 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20150518090554/http://www.ncpa.org/pub/st218?pg=4 |archive-date=2015-05-18 }}</ref> However, according to other studies from the 1960s and 1970s, "contrary to popular belief, Miranda had little, if any, effect on detectives' ability to solve crimes."<ref name="HeritageApril" />