MINNEAPOLIS, Minnesota - The prosecutor in the Minnesota county where Prince died said evidence shows Prince -- who died from an accidental fentanyl overdose -- thought he was taking Vicodin, not fentanyl. Carver County Attorney Mark Metz said evidence showed that Prince took counterfeit Vicodin without knowing it. 

Metz also said Thursday there's no evidence any of the people surrounding Prince gave him counterfeit Vicodin or knew he had it. And he announced he's filing no criminal charges in the musician's death, meaning the state's investigation into how Prince got the fentanyl that killed him is closed. 

Prince was 57 when he was found alone and unresponsive in an elevator at his Paisley Park estate in suburban Chanhassen on April 21, 2016. An autopsy found he died of an accidental overdose of fentanyl, a synthetic opioid 50 times more powerful than heroin. 

A confidential toxicology report, obtained in March by The Associated Press, showed high concentrations of fentanyl in the singer's blood, liver and stomach. The concentration of fentanyl in Prince's blood was 67.8 micrograms per liter, which outside experts called "exceedingly high." The report noted that fatalities have been documented in people with blood levels ranging from 3 to 58 micrograms per liter.

Search warrants unsealed about a year after Prince died showed that authorities searched his home, cellphone records of associates and his email accounts to try to determine how he got the drug. Authorities found numerous pills in various containers stashed around Prince's home, including some counterfeit pills that contained fentanyl. The source of that fentanyl was never determined.

While many who knew Prince over the years said he had a reputation for clean living, some said he also struggled with pain after years of intense performances. Documents released by authorities last year paint a picture of a man struggling with an addiction to prescription opioids and withdrawal, and they also show there were efforts to get him help.

Six days before he died, Prince passed out on a plane and an emergency stop was made in Moline, Illinois. The musician had to be revived with two doses of a drug that reverses the effects of an opioid overdose. The day before his death, Paisley Park staffers contacted California addiction specialist Dr. Howard Kornfeld as they were trying to get Prince help. Kornfeld sent his son, Andrew, to Minnesota that night and the younger Kornfeld was among those who found Prince's body. Andrew Kornfeld was carrying buprenorphine, a medication that can be used to help treat opioid addiction.

This week, a Minnesota doctor accused of illegally prescribing an opioid painkiller for Prince a week before he died agreed to pay $30,000 to settle a federal civil violation, according to documents made public Thursday. The settlement between the U.S. Attorney's Office and Dr. Michael Todd Schulenberg, dated Monday, does not name Prince or make any references to the Prince investigation, but search warrants previously released say Schulenberg told authorities he prescribed oxycodone to Prince on April 14 and put it under the name of Prince's bodyguard and close friend, Kirk Johnson, "for Prince's privacy." Schulenberg's attorney has disputed that. 

Federal prosecutors and the U.S. Drug Enforcement Administration alleged Schulenberg, a family physician who saw Prince at least twice before he died, violated the Controlled Substances Act when he wrote a prescription in the name of someone else on April 14, 2016.   

The settlement notes that the agreement "is neither an admission of facts nor liability by Dr. Schulenberg." And in a separate letter to Schulenberg's attorneys, prosecutors say Schulenberg is not currently a target of any criminal investigation.