CA1: A party can’t concede an issue in the papers and then argue against it on appeal

Defense counsel can’t concede a Fourth Amendment issue in the papers and then argue against it on appeal. United States v. Gates, 709 F.3d 58 (1st Cir. 2013):

In his motion to suppress, the defendant explicitly “concede[d] that based upon his speed Officer Hall had a reasonable articulable suspicion to effect a traffic stop of his vehicle.” This concession corresponds to the officer’s account and no more is exigible to render the stop legitimate. See Whren v. United States, 517 U.S. 806, 812-13 (1996) (holding that the appropriate Fourth Amendment test is one of objective reasonableness); Ruidíaz, 529 F.3d at 29 (same). That ends this aspect of the matter: a party cannot concede an issue in the district court and later, on appeal, attempt to repudiate that concession and resurrect the issue. To hold otherwise would be to allow a litigant to lead a trial court down a primrose path and later, on appeal, profit from the invited error. We will not sanction such tactics. Cf. Merchant v. Ruhle, 740 F.2d 86, 92 (1st Cir. 1984) (warning against permitting the use of “agreeable acquiescence to perceivable error as a weapon of appellate advocacy”).