The McNabb-Mallory rule (sometimes referred to as just the Mallory rule) is the U.S. rule of evidence that a confession is inadmissible if obtained during an unreasonably long period of detention between arrest and initial court appearance.[1] [2] [3] [4]
The rule was largely superseded by the broader protections provided for under the Miranda rules.
The rule opened a line of cases which referenced a unique power of the Supreme Court to exercise a supervisory power in law enforcement, evidence, and procedure in federal courts.[5]