That prescription was written six days before Prince's death, when he overdosed on a plane heading home from a concert in Atlanta.

First responders revived him that time with two doses of a drug that reverses the effects of an opioid overdose.

Most fatal opioid overdoses that are investigated never lead to criminal charges, said Kerry Harvey, a former U. attorney for eastern Kentucky who made prosecuting such cases a high priority.

A common problem is that evidence gets destroyed by first responders focused on saving a life.

Only one tested positive for fentanyl, and police continue to investigate how he got the drug - which he did not have a prescription for.