Colorado v. Spring
United States Supreme Court
479 U.S. 564 (1987)
After a sting operation, federal agents arrested Spring (defendant) for illegal firearms sales, read him Miranda warnings, and obtained a signed waiver before questioning him about the firearms deal; when agents unexpectedly asked if he had ever shot anyone, he admitted he had, and in later questioning confessed to a murder. The Colorado Supreme Court found the waiver invalid because agents never told Spring they might ask about a shooting, rendering the subsequent murder confession inadmissible; the U.S. Supreme Court granted certiorari.
Whether a suspect must be aware of all the possible subjects of questioning in advance of interrogation for the suspect's waiver of his Fifth Amendment rights to be voluntary, knowing, and intelligent.