United States prosecutors are looking to hold people criminally accountable for overdose deaths. They’re settling on unexpected targets: other users. Guests: Annie Brown, a producer for “The Daily,” speaks to Kimberly Elkins, whose fiancé, Aaron Rost, died of a fentanyl overdose; Krista Powell, Mr. Rost’s sister; and Rosa Goldensohn, who has reported on the opioid crisis for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily.