What is the burden of proving that "everybody knows that police use cameras when responding to domestic violence complaints"?

This claim fails for two reasons. First, he offers no evidence, other than his own unsupported assertions, that any of the testimony offered against him was false. The claim that "everybody knows" that police use cameras when responding to domestic violence complaints is insufficient to establish that they did so in this case. Moreover, to the extent any witness offered contradictory or conflicting statements on the stand (as petitioner alleges one of the officers did), the jury was able to consider those contradictions in reaching its verdict. Second, petitioner has failed to establish that the prosecutor knew any of the testimony presented to be false. See United States v. Polizzi, 801 F.2d 1543, 1549-50 (9th Cir. 1986). At best, he offers only his own, unsupported speculation that the prosecutor knowingly used false testimony. Mere speculation cannot carry his burden. United States v. Aichele, 941 F.2d 761, 766 (9th Cir. 1991).