What is the current state of the law on police failure to preserve physical evidence in the context of police misconduct?

Arizona v. Youngblood (1988) 488 U.S. 51 (Youngblood) addressed the negligent failure of police to preserve physical evidence "of which no more can be said than that it could have been subjected to tests, the results of which might have exonerated the defendant." (Id. at p. 57, 109 S.Ct. 333.) In this instance, the high court held that there is no due process violation unless the defendant could show bad faith on the part of the police. (Id, at p. 58, 109 S.Ct. 333.)