In a Manhattan courtroom earlier this month, Arkansas doctor David Churchill described the day he found the body of his 27-year-old son, Reed, after a fatal dose of fentanyl: half on the couch, half on the floor, “cold and dead and stiff,” as Churchill told the court.“As you might imagine, it was the worst day of my life,” the father said, standing beside his wife and suppressing tears. “We've been gutted by this, and we have to live with it every day.”Churchill was speaking at the sentencing he...