the plea. 4 . In the district court, both Defendants also challenged the second search of the Cadillac that occurred several days after Defendants' arrest. On appeal, however, neither Defendant reasserts that argument. 5 . The Government may be deemed itself to waive a defendant's appeal waiver if the Government does not assert a motion to enforce the plea agreement or seek to enforce that agreement in its appellate brief. See United States v. Hahn, 359 F.3d 1315, 1328 (10th Cir.2004) (en banc) (per curiam); see also United States v. Smith, 500 F.3d 1206, 1210 n. 1 (10th Cir.2007). In Richardson's case, the Government did expressly seek to enforce Richardson's appeal waiver in its answer brief filed with this court. See United States v. Trujillo, 537 F.3d 1195, 1202 (10th Cir.2008) (<HOLDING>); see also United States v. Ibarra-Coronel, 517
holding government can seek to enforce a defendants appeal waiver in the governments merits brief holding that failure to brief an argument constitutes waiver holding that failure to raise issue in brief constitutes waiver of appeal of the issue holding failure to brief argument constitutes waiver recognizing that courts will enforce waiver of appeal rights when waiver is knowing and voluntary