## Facts

- From 1992 to 1995, Paiboon Mekvichitsang repeatedly bought heroin from suppliers Zagar Kovittamakron and Throngboon Kulkovit, sometimes receiving heroin on credit (“fronted”).
- Deliveries were made both directly to Mekvichitsang and, at his direction, to Sunthorn Yossunthorn, whom Mekvichitsang described as “one of his workers.”
- Transactions involved amounts ranging from four ounces to one pound, with pricing varying over time; on at least one occasion Mekvichitsang made only partial payment, and on another he returned heroin due to poor quality.
- On December 4, 1995, Kovittamakron told Mekvichitsang he expected another heroin shipment, and Mekvichitsang expressed interest in purchasing some of it.
- After Kovittamakron’s arrest, he cooperated with law enforcement and recorded phone calls with Mekvichitsang from December 5–7, 1995.
- On December 6, Kovittamakron told Mekvichitsang the heroin had arrived; Mekvichitsang proposed meeting at a nearby McDonald’s at noon on December 7 to “make arrangements” for a possible transaction (quantity, price, and delivery terms).
- Kovittamakron refused to meet on December 7; agents nonetheless surveilled the McDonald’s area and observed conduct they characterized as countersurveillance by Mekvichitsang and Yossunthorn.
- Agents arrested both defendants near the McDonald’s before any transfer occurred; no heroin was present or exchanged at the meeting site.
- A jury convicted both defendants of attempted possession with intent to distribute heroin; Mekvichitsang was also convicted of conspiracy to distribute heroin. The district court denied post-verdict acquittal motions.

## Issues

1. Whether the evidence was sufficient to prove attempted possession with intent to distribute heroin, including whether defendants took a “substantial step” beyond mere preparation.
2. Whether Mekvichitsang’s long-term dealings with suppliers and related conduct sufficiently proved conspiracy to distribute heroin.
3. Whether Yossunthorn’s attempt conviction, premised on Pinkerton liability, could stand if the underlying attempt by a co-conspirator was not proved.

## Decision

- The Ninth Circuit reversed both defendants’ convictions for attempted possession with intent to distribute heroin due to insufficient evidence of a substantial step.
- The court affirmed Mekvichitsang’s conspiracy conviction, holding the evidence adequately showed an agreement to distribute heroin.
- Because Yossunthorn’s attempt conviction was derivative under Pinkerton, it was reversed once Mekvichitsang’s attempt conviction failed.

## Legal Principles

- An attempt conviction requires proof of intent to commit the offense and a “substantial step” toward completion that is more than preparation and strongly corroborates the firmness of the criminal intent.
- Conduct aimed at arranging or negotiating a future drug deal, without an agreement on essential terms and without any drugs available for acquisition at that time, may be insufficient to constitute a substantial step toward possession.
- Pinkerton liability for a substantive offense requires that the substantive offense be established as to at least one conspirator; if the underlying offense fails, derivative liability fails.
- Conspiracy may be proved through circumstantial evidence of an ongoing agreement, including repeated large-quantity transactions, credit/fronting arrangements, and corroborated testimony.

## Conclusion

The Ninth Circuit held that surveillance-like conduct and travel to a proposed meeting to discuss terms of a possible heroin purchase amounted to preparation, not a substantial step toward possession, requiring reversal of the attempt convictions, while affirming Mekvichitsang’s conspiracy conviction based on evidence of a sustained heroin distribution agreement.


United States v. Yossunthorn, 167 F.3d 1267 (9th Cir. 1999)