NCIS investigation of state law offenses committed by civilians violated Posse Comitatus Act (PCA) (18 U.S.C. § 1385), but suppression of evidence was not required. Naval Criminal Investigative Service (NCIS) Agent Logan conducted an investigation for online criminal activity in the State of Washington. He found evidence of a computer accessing child pornography and turned the matter over to state authorities. Based on evidence developed by state and federal law enforcement acting on Agent Logan’s information, Dreyer was ultimately convicted of federal child pornography charges and sentenced to prison. He appealed the denial of his motion to suppress evidence. The case was heard en banc. Held: Affirmed. Direct military enforcement of civilian laws is generally prohibited by the PCA. Although the PCA expressly refers only to the Army and Air Force, the Navy and Marines are likewise included because PCA-like restrictions apply as a matter of Department of Defense policy. NCIS agents are similarly restricted, even though many are civilians. (United States v. Chon (9th Cir. 2000) 210 F.3d 990, 993-994.) There is an exception to PCA where the military indirectly assists civilian law enforcement, or where an independent military purpose exists. Here, Agent Logan’s surveillance of all computers in Washington, which he instigated, was not focused on military or government computers, and was therefore prohibited by PCA. Although the appellate court noted that the case presented “troubling violations,” it concluded that suppression of the evidence was not warranted. The Supreme Court has sanctioned the application of the exclusionary rule to vindicate statutory violations only rarely, and excluding the evidence obtained in this case would do little to correct an investigative operation that was the result of institutional error in the military’s command structure rather than deliberate disregard of statutory constraints.