United States v. Charles Foster, 664 F. App'x 644

Charles Foster was convicted by a jury of: possession with intent to distribute ≥50g methamphetamine; possession with intent to distribute cocaine; and conspiracy to possess ≥500g mixture containing methamphetamine and cocaine. Appeals court review under 28 U.S.C. § 1291.
At trial the government introduced: Foster’s 2007 prior drug-distribution conviction and evidence of two prior transactions with a confidential informant; police also executed a search warrant finding the controlled substances in Foster’s house.
Foster argued he lacked knowledge of the drugs’ presence; the government relied on the prior conviction and prior transactions to prove intent and knowledge (and to support the conspiracy charge).
The government’s chemical analyst (Amanda Pontius) testified about drug testing; Foster challenged foundation/calibration testimony for the instruments used.
During testimony, Agent Grant Knorr made an erroneous date entry on a consent-to-search form; the district judge questioned the agent to clarify the mistake, and Foster later argued judicial misconduct based on that colloquy.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admission of prior conviction and prior drug transactions under Fed. R. Evid. 404(b)	Prior conviction and transactions were unfair propensity evidence and should be excluded	Evidence was admissible: (1) probative of knowledge/intent, (2) not too remote, (3) sufficient to support finding, (4) factually similar; prior transactions also directly relevant to conspiracy (not 404(b))	Court affirmed admission; 404(b) four-factor test satisfied and transactions admissible as direct evidence of the conspiracy
Foundation for forensic chemist’s testimony	Pontius did not testify the instruments were functioning or calibrated properly, so her testimony lacked foundation	Pontius described performance checks and how she knew equipment functioned properly	Court held district court did not abuse discretion in admitting the expert’s testimony
Judicial misconduct / district judge questioning Agent Knorr	District court’s extensive questioning of the agent constituted improper judicial participation and prejudiced Foster	Judge’s participation was proper to clarify confusing testimony about an obvious clerical date error	Reviewed for plain error; court found no misconduct—judge’s questioning was proper to clarify evidence

United States v. Romero, 282 F.3d 683 (9th Cir.) (framework for Rule 404(b) review)
United States v. Vo, 413 F.3d 1010 (9th Cir.) (four-part test for admitting prior-act evidence)
United States v. Rude, 88 F.3d 1538 (9th Cir.) (age of prior conviction not necessarily too remote)
United States v. Ross, 886 F.2d 264 (9th Cir.) (prior convictions admissible despite temporal gap)
United States v. Curtin, 489 F.3d 935 (9th Cir.) (abuse-of-discretion standard for admission of expert evidence)
United States v. Bosch, 951 F.2d 1546 (9th Cir.) (plain-error review when no timely objection made)
United States v. Mostella, 802 F.2d 358 (9th Cir.) (permissible judicial participation to clarify testimony)