Source: https://www.justice.gov/jm/criminal-resource-manual-1779-prison-offenses-knowledge-warden
Timestamp: 2019-04-18 12:22:08+00:00

Document:
Lack of knowledge by the warden becomes an issue if the regulation being violated under 18 U.S.C. § 1791 is 28 C.F.R. § 6.1. 28 C.F.R. § 6.1 requires that the offense occur without the knowledge of the warden.
In United States v. Berrigan, 482 F.2d 171, 188 (3d Cir. 1973), the Court of Appeals held that the warden's lack of knowledge regarding the sending and receiving of letters was an essential element of the crime. If the warden knew of the letters there could be no crime. This constituted "legal" impossibility and, therefore, was a valid defense to a charge of attempt. This analysis has not, however, been accepted by all courts of appeals. See United States v. Heng Awkak Roman, 356 F. Supp. 434 (S.D.N.Y. 1973), aff'd, 484 F.2d 1271 (2d Cir. 1973)(per curiam), cert. denied, 415 U.S. 978 (1974); United States v. Quijada, 588 F.2d 1253 (9th Cir. 1978); United States v. Frazier, 560 F.2d 884 (8th Cir. 1977), cert. denied, 435 U.S. 968 (1978).
In contrast to the Berrigan situation, however, when the contraband is intercepted and then allowed to proceed, the attempt would be already complete prior to the interception. A warden's lack of knowledge or consent can be inferred beyond reasonable doubt from other evidence. See United States v. York, 578 F.2d 1036 (5th Cir.), cert. denied, 439 U.S. 1005 (1978).

References: § 1791
 § 6
 § 6
 v. 
 v. 
 v. 
 v. 
 v.