The following excerpt is from USA v. Cormier, 220 F.3d 1103 (9th Cir. 2000):
There are two exceptions to the general rule that state law violations do not require suppression of evidence in federal court. The first exception arises when a court is determining the legality of an inventory search, see United States v. Wanless, 882 F.2d 1459, 1463 (9th Cir. 1989), because "federal law on inventory searches by state or local police officers [requires] that they must be conducted in accordance with the official procedures of the relevant state or local police department." Id. at 1464. The second exception arises in searches incident to arrest, see United States v. Mota , 982 F.2d 1384, 1388 (9th Cir. 1993), because "federal courts must determine the reasonableness of the arrest in reference to state law governing the arrest." Id. at 1388.
The above passage should not be considered legal advice. Reliable answers to complex legal questions require comprehensive research memos. To learn more visit www.alexi.com.