Is a failure to preserve or collect only potentially useful evidence a denial of due process?

The state's failure to preserve or collect evidence that is only potentially useful is not a denial of due process unless the defendant shows bad faith on the part of the police and shows that the loss of evidence prejudiced the defendant's case. Arizona v. Youngblood, 488 U.S. 51, 58 (1988); California v. Trombetta, 467 U.S. 479, 488-09 (1984); United States v. Dring, 930 F.2d 687, 693 (9th Cir.1991), cert. denied, 113 S.Ct. 110 (1992). To establish prejudice, the defendant "must at least make a plausible showing that the [evidence] ... would have been material and favorable to his defense, in ways not cumulative to [other evidence]." Dring, 930 F.2d at 693-94 (quotation omitted).