Justin Case Lebarron helped distribute the fentanyl-and-methamphetamine mixture that killed a former associate, identified in the opinion as J.B. The jury imposed the Controlled Substances Act’s death-result enhancement, producing concurrent life sentences, and Lebarron argued that the instruction failed to require the right causal connection between his conduct and the overdose. The Eleventh Circuit held that the government’s proof and instruction satisfied its causation precedent and affirmed the convictions and life sentences; separate opinions warned that the rule can impose life imprisonment without a finding that the defendant foresaw the death.