Phelps was the only one charged in connection with an overdose. In a statement at the time, U.S. Attorney Steven Dettelbach said the heroin Phelps allegedly provided "directly contributed to an overdose death."
But the Supreme Court, in its Jan. 27 opinion, said federal law "requires death to 'result from' use of the [illegal] drug, not from a combination of factors to which drug use merely contributed."
The Supreme Court decision in Burrage v. United States initially received scant news coverage and only moderate notice since actor Hoffman's overdose -- a case being handled by local authorities in New York that highlights some of the obstacles to bringing federal charges.
Still, top federal prosecutors said they don't believe the high court's decision is "a significant setback" or "a real game-changer for us."
Medical experts will just have to dig deeper to determine a drug's exact role in death, and federal prosecutors rarely seek the stiffer charge anyway, even when an overdose occurs, according to both Coffin and Harvey, the U.S. attorneys.
"We're going to be fine" and will bring "most of the cases we want to bring," Harvey said.
But the Justice Department official, speaking on condition of anonymity, said finding medical experts who can determine a drug's exact role is not so easy and "is a big burden on the government." Plus, the official said, the Supreme Court decision could be "a blow" to investigative efforts.
"The 20-year mandatory minimum has been tremendously efficient in scaring the dickens out of people so they cooperate up the chain," the official said. "It's been a really good negotiating tool."
Coffin wasn't so worried, saying prosecutors still have "so many others levers" and "really tough penalties" to induce cooperation.
One thing everyone agreed on: The Supreme Court decision could bring a "new battlefield" in federal overdose cases, with prosecutors shifting attention away from "death" and toward "serious bodily injury" cited in the same law.
"There will be some cases that … we'll have to do in a different way," Coffin said.
After all, it may now be easier to prove a dealer's drug seriously damaged a vital organ than killed the person.
It's "a new area" prosecutors "will have to focus on," Coffin said.