United States v. Joaquin Vicencio, 647 F. App'x 170

In June–July 2013 authorities discovered multiple marijuana plots and a nearby campsite in the George Washington National Forest (federal land); officers arrested Joaquin Gonzalez Vicencio and Joaquin Berumen Cortes at the campsite and seized nearly 5,000 marijuana plants and hazardous-chemical containers.
Both defendants admitted tending and planting large numbers of marijuana plants, left notes/photographs corroborating their activities, and made post‑arrest statements admitting involvement.
A jury convicted both defendants of conspiracy and marijuana manufacturing (Counts One and Two), and of using hazardous substances on federal land causing environmental harm (Count Three). Berumen Cortes was also convicted of illegal reentry (Count Four).
At sentencing Berumen Cortes sought a safety‑valve reduction under 18 U.S.C. § 3553(f) to avoid a 120‑month statutory minimum; the district court denied § 3553(f) relief for failure to make a complete and truthful disclosure and imposed 120 months.
On appeal the defendants (1) for the first time argued the government failed to prove that they knew they were on federal land for purposes of § 841(b)(6), and (2) Berumen Cortes challenged denial of safety‑valve relief. The Fourth Circuit affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether § 841(b)(6) requires proof the defendant knew the land was federal when using hazardous substances	Gonzalez Vicencio & Berumen Cortes: § 841(b)(6) requires knowledge that the land was federal; govt failed to prove that knowledge	Government: mens rea limited to knowingly/ intentionally using hazardous substance; defendants forfeited the issue by not raising it below	Court: Issue was forfeited and defendants did not meet the exacting plain‑error standard; no plain error found (assumed error but not "plain") — conviction on Count Three affirmed
Whether district court clearly erred denying § 3553(f) safety‑valve relief to Berumen Cortes	Berumen Cortes: he provided all information he knew (post‑arrest statements and PSR interview) and should receive safety‑valve relief	Government: he did not make a complete, truthful disclosure at the proffer; prosecutors could not obtain full details because proffer was not completed	Court: Denial was not clearly erroneous; record supports finding he failed to fully disclose (e.g., notepad entries contradicted his one‑week claim) — safety‑valve denial affirmed

United States v. Olano, 507 U.S. 725 (standard for plain error review)
Puckett v. United States, 556 U.S. 129 (importance of timely objection; purposes of plain‑error rule)
United States v. Byers, 649 F.3d 197 (strictness of plain‑error review in Fourth Circuit)
United States v. Shepperson, 739 F.3d 176 (no plain error where issue unsettled among circuits)
United States v. Carthorne, 726 F.3d 503 (elements of Olano analysis)
United States v. Godwin, 272 F.3d 659 (assuming error for Olano review)
United States v. Henry, 673 F.3d 285 (elements and burden for safety‑valve relief)
United States v. Aidoo, 670 F.3d 600 (defendant bears burden to prove full, truthful safety‑valve disclosure)
United States v. Perry, 757 F.3d 166 (standard for reviewing evidence in favor of the government)
United States v. McManus, 734 F.3d 315 (harmlessness of sentencing error when result remains within mandatory minimum)