Waiving Evidentiary Claims: An Illustrative Case

United States v. Cohen, 887 F.3d 77 (1st Cir. 2018), illustrates (a) how a defendant in a criminal case can lose the right to appeal evidence rulings by entering into an agreement with the government that moots a ruling by the trial judge, and (b) how defense counsel’s failure to understand a judge’s ruling may lead to an agreement that actually provides no benefit to the defense.