FILE - In this Feb. 4, 2007 file photo, Prince performs during the halftime show at the Super Bowl XLI football game at Dolphin Stadium in Miami. A Minnesota doctor accused of illegally prescribing an... (Associated Press) 
 
 FILE - In this Feb. 4, 2007 file photo, Prince performs during the halftime show at the Super Bowl XLI football game at Dolphin Stadium in Miami. A Minnesota doctor accused of illegally prescribing an opioid painkiller for Prince a week before the musician died from a fentanyl overdose has agreed to... (Associated Press) 
 
 MINNEAPOLIS (AP) — The prosecutor in the Minnesota county where Prince died said Thursday that no criminal charges will be filed in the musician's death, effectively ending the state's two-year investigation into how Prince got the fentanyl that killed him. 
 
 Carver County Attorney Mark Metz's announcement on no criminal charges came just hours after documents revealed that a doctor who was accused of illegally prescribing an opioid for Prince had agreed to pay $30,000 to settle a federal civil violation. Prosecutors alleged Dr. Michael Todd Schulenberg wrote a prescription for oxycodone in the name of Prince's bodyguard, intending it to go Prince. 
 
 Metz said the evidence shows Prince thought he was taking Vicodin, not fentanyl. He said there's no evidence any person associated with Prince knew he possessed any counterfeit pill containing fentanyl. 
 
 Prince was 57 when he was found alone and unresponsive in an elevator at his Paisley Park studio compound on April 21, 2016. His death sparked a national outpouring of grief, and prompted a joint investigation by Carver County and federal authorities. 
 
 An autopsy found Prince died of an accidental overdose of fentanyl, a synthetic opioid 50 times more powerful than heroin. State and federal authorities have been investigating the source of the fentanyl for nearly two years, and have still not determined where the drug came from or how Prince got it. 
 
 While Carver County said it was ending its role in the case, the U.S. Attorney's Office had no immediate comment on the status of its investigation. 
 
 But a law enforcement official close to the investigation told The Associated Press that the federal investigation is now inactive unless new information comes forward. The official spoke on condition of anonymity because the case remains open. 
 
 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, dated Monday, does not name Prince or make any references to the Prince investigation. However, 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, Amy Conners, has disputed that and did so again on Thursday, saying that Schulenberg settled the case to avoid the expense and uncertain outcome of litigation. 
 
 Oxycodone, the generic name for the active ingredient in OxyContin, was not listed as a cause of Prince's death. But it is part of a family of painkillers driving the nation's overdose and addiction epidemic, according to the U.S. Centers for Disease Control and Prevention. Nearly 2 million Americans abused or were addicted to prescription opioids, including oxycodone, in 2014. 
 
 A laboratory report obtained by The Associated Press notes that one of the pills found in a prescription bottle in Paisley Park that bore Johnson's name tested positive for oxycodone. 
 
 "Doctors are trusted medical professionals and, in the midst of our opioid crisis, they must be part of the solution," U.S. Attorney Greg Brooker said in a statement Thursday. 
 
 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. 
 
 Under the settlement, Schulenberg also agreed to stricter requirements for logging and reporting his prescriptions of controlled substances for two years, and give the DEA access to inspect those records. 
 
 It's illegal for a doctor to write a prescription for someone under another person's name. Anyone convicted of doing so could lose their DEA registration — meaning they could no longer prescribe controlled substances — and could face discipline from their state medical board. 
 
 The settlement says the DEA won't revoke Schulenberg's registration, unless he does not comply. It's unclear whether the state medical board will take action. His license is currently active and he has no disciplinary action against him. 
 
 A confidential toxicology report obtained by the AP in March showed high concentrations of fentanyl in the singer's blood, liver and stomach. The concentration of fentanyl in Prince's blood alone was 67.8 micrograms per liter, which outside experts called "exceedingly high." 
 
 Prince did not have a prescription for fentanyl. Search warrants unsealed about a year after he 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. 
 
 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 performing at an intense level. Documents unsealed 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. 
 
 Associates at Paisley Park told investigators that Prince was recently "going through withdrawals, which are believed to be the result of the abuse of prescription medication," according to an affidavit. 
 
 Just 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. 

 Video (16:12) : Carver County Attorney Mark Metz announced Thursday that he was closing the two-year investigation into the death of Prince without issuing any criminal charges. 
 
 Carver County Attorney Mark Metz announced Thursday that he was closing the two-year investigation into the death of musician Prince Rogers Nelson without issuing any criminal charges. 
 
 Metz said county, state and federal investigators undertook an “extensive, painstaking and thorough” investigation but were unable to determine who provided Prince the fentanyl painkillers, disguised as counterfeit prescription medication, that killed the megastar on April 21, 2016. 
 
 Metz said there was no evidence that Prince or his associates knew that Prince had taken counterfeit pills marketed under the trade name Vicodin, or that anyone had conspired to kill him. 
 
 “There is no reliable evidence showing how Prince obtained the counterfeit Vicodin containing fentanyl,” he added. “The bottom line is that we simply do not have sufficient evidence to charge anyone with a crime related to Prince’s death.” 
 
 After the news conference, a spokeswoman for the U.S. attorney’s office said that federal prosecutors have so far received no credible evidence that would lead to any federal criminal charges. A law enforcement source with direct knowledge of the case said it is now inactive pending the uncovering of additional evidence or witnesses. 
 
 Ninety minutes before Metz spoke, the U.S. attorney’s office in Minnesota announced that it had agreed to a civil settlement with a Minnesota doctor who admitted that he knew that painkillers he had prescribed for Prince’s bodyguard and longtime associate, Kirk Johnson, would be used by the musician. The settlement resolves possible controlled substance violations found during the death investigation. 
 
 Dr. Michael T. Schulenberg will pay a $30,000 fine and will also be monitored under a two-year agreement with the U.S. Drug Enforcement Administration as part of the settlement. 
 
 Neither the names of Prince nor Johnson appear in the settlement agreement, but federal search warrants executed in the weeks after Prince’s body was discovered at his Paisley Park studio in Chanhassen disclosed that Schulenberg admitted to writing prescriptions for Percocet in Johnson’s name, knowing that they were actually for Prince. 
 
 Investigators do not suspect Schulenberg of supplying the fentanyl that caused Prince’s death. 
 
 Prince, 57, died of a massive overdose of fentanyl on April 21, 2016, according to the medical examiner. The Star Tribune first reported that pills marked as prescription painkillers seized at the death scene were found to contain fentanyl. 
 
 An autopsy revealed so much fentanyl in Prince’s system that it would have been fatal for anyone, regardless of their size or drug tolerance. 
 
 According to a federal search warrant application unsealed early Thursday, a medical examiner found 67 micrograms of fentanyl per liter of blood in Prince’s system — more than 22 times what would be found in a cancer patient who regularly wore a pharmaceutical fentanyl patch. 
 
 In a statement Thursday, Amy Conners, an attorney for the doctor, said Schulenberg affirmed a previous statement that he did not prescribe opiates to any patient with the intention that they be given to Prince. However, the U.S. attorney’s office contends that Schulenberg knowingly made a prescription “in the name of an individual, knowing that the controlled substances were intended to be used by another individual.” 
 
 “Doctors are trusted medical professionals and, in the midst of our opioid crisis, they must be part of the solution,” U.S. Attorney Greg Brooker said in a statement announcing the settlement. “As licensed professionals, doctors are held to a high level of accountability in their prescribing practices, especially when it comes to highly addictive painkillers. The U.S. attorney’s office and the DEA will not hesitate to take action against healthcare providers who fail to comply with the Controlled Substances Act. We are committed to using every available tool to stem the tide of opioid abuse.” 
 
 According to the agreement, Schulenberg and the U.S. attorney’s office reached the settlement to “avoid the delay, uncertainty, inconvenience, and expense of protracted litigation of these claims ….” 
 
 However, the agreement is made “in compromise of disputed claims.” Schulenberg did not admit liability nor did the government make any concessions “that its claims are not well-founded.” 
 
 “After he learned of Prince’s addiction, he immediately worked to refer Prince to a treatment facility and to transfer care to a chemical dependency specialist,” Conners said Thursday. “Dr. Schulenberg has previously disclosed all information regarding his care and treatment of Prince to his employers, law enforcement, and regulatory authorities in the course of his complete cooperation with all related investigations.” 
 
 The U.S. attorney’s office also agreed not to revoke or suspend Schulenberg’s DEA registration unless he violated his agreement with the DEA. 
 
 Schulenberg is a licensed physician doing business at Fairview Clinics in New Brighton and has been licensed since 1997 in Minnesota. 
 
 New federal documents 
 
 According to a second previously sealed federal search warrant application from 2016, Schulenberg, who was Johnson’s doctor, told investigators at the death scene that he examined Prince at Johnson’s request two weeks earlier and administered intravenous fluids. 
 
 Schulenberg initially denied prescribing medication but said he prescribed anti-nausea drugs and vitamin D for Prince. Instead, he issued the drugs in Johnson’s name. 
 
 Schulenberg also admitted that Johnson asked him to prescribe pain medication to Prince on April 14, a week before the musician’s death, because Prince was experiencing hip pain and had a concert that night in Atlanta — the show would be notable for being his last full concert. 
 
 Schulenberg did not see Prince that day but agreed to write a prescription for 15 tablets of Percocet, a form of oxycodone, intended for Prince but made out in Johnson’s name. According to a DEA task force officer, in his notes, Schulenberg wrote that Johnson “called and is leaving town for Atlanta for a concert shortly and hurt his back lifting equipment.” 
 
 On the return trip to the Twin Cities from the Atlanta show, Prince’s private plane made an emergency landing in Moline, Ill., after Prince passed out. Paramedics scrambled to revive him on the tarmac, and he recovered after two shots of naloxone, an overdose antidote often referred to by its brand name Narcan. Johnson told doctors in Moline that Prince may have taken Percocet. He was documented as suffering from an opiate overdose but refused treatment at the hospital. 
 
 Schulenberg told investigators that three days after the emergency landing, or four days before Prince died, Johnson sent a text message asking Schulenberg to call him. During the call, Schulenberg told investigators, Johnson expressed concerns about Prince’s opiate use and apologized for asking Schulenberg to prescribe Percocet for Prince. 
 
 As part of the settlement this week, Schulenberg also entered into a “Memorandum of Agreement” with the DEA under which he agreed to comply with a two-year period of heightened compliance for logging and reporting of all of his prescriptions of controlled substances — including quantity, strength, dosage and diagnoses. 
 
 Under the agreement, DEA personnel can also enter his office without notice at any time during business hours to ensure compliance. Schulenberg must submit logs on a quarterly basis and allow the DEA access to his prescribing history through Minnesota’s Prescription Monitoring Program. He must also provide a prescribing history report to the DEA from the Minnesota Board of Pharmacy. 
 
 “As Minnesota and the Nation struggle in the throes of an opioid crisis, the Drug Enforcement Administration will always strive to ensure that those responsible will be held accountable, no matter what their position may be,” said Kenneth Solek, assistant special agent in charge of the DEA’s Twin Cities division. 
 
 Doctor not a federal target 
 
 Brooker, meanwhile, wrote a letter to Schulenberg’s attorneys, Conners and Thomas Heffelfinger, earlier this week clarifying prosecutors’ intentions with respect to their client. 
 
 “I understand his concern to be whether, in the view of this office, he is currently the target of a criminal investigation. In the context of a criminal investigation, a ‘target’ is a person who is linked by substantial evidence to the commission of a crime and who, in the prosecutor’s judgment, is likely to be charged. At this time, Dr. Schulenberg is not a target of any criminal investigation.” 
 
 Medical records indicated that Schulenberg examined Prince a day before his death, according to one federal search warrant. The musician reported feeling “antsy” and thought it may be related to having stopped taking Tylenol that morning. Prince didn’t know if the Tylenol had other ingredients, Schulenberg said. But Schulenberg’s notes indicated that “independent sources of history” reported Prince’s Tylenol as containing hydrocodone, a pain reliever. A urinalysis on Prince also tested positive for opiates. 
 
 The records also show Schulenberg expressed concern that Prince could be suffering from opiate withdrawal. 
 
 Federal search warrants described DEA investigators seeking evidence of federal drug crimes that included distribution and conspiracy charges. Weeks after Prince’s death, agents found dozens of pills marked as prescription pain pills in Prince’s bedroom, inside two bottles of CVS-brand vitamin C tablets in a black suitcase. 
 
 Agents also recovered a CVS prescription pill container with 10 white round pills with “TV150” stamped on one side and “3” on another, which indicates an acetaminophen/codeine mixture. But, according to the search warrants, those pills were thought to be an unused prescription written by a Minnesota dentist for Johnson. 
 
 On Thursday, Johnson’s attorney, F. Clayton Tyler, said Johnson was relieved to learn that no charges had been filed against him. 
 
 “He continues to deny that he had anything to do with the death of his close friend, Prince,” Tyler said. “Prince’s death was a tragedy that few could experience more deeply than Kirk Johnson. Today’s decision affirms his innocence, and he will continue to mourn and honor his friend every day.” 
 
 Fans react 
 
 Kimberlee Andrus, stay-at-home mom from Austin, Minn., drove more than 90 minutes to the Carver County Courthouse to attend Thursday’s news conference. Donning purple hair, a purple blouse and a giant Prince symbol, she left disappointed after learning that no one would face criminal charges. 
 
 “I honestly believe there was foul play, and I’m not the only one,” said Andrus, 39. After more than three decades of listening to Prince’s music, she said she felt a close personal connection to the late musician and has spent the last two years investigating his death along with other fans. 
 
 “I lost my brother,” Andrus said. “I wanted to see if justice was brought to someone I love and cared dearly about for many years.” 
 
 She vowed to keep digging until someone is held accountable for Prince’s overdose. 
 
 Gary Schmitz, sporting a T-shirt depicting Prince riding a Segway, said he’d hoped for a different outcome. 
 
 “I just hope no one lied to protect someone,” said Schmitz, a retired mechanical inspector from Shakopee. “They can’t keep the secret forever.” 
 
 Schmitz described himself as a Prince fan since Day One. The musician’s appeal is hard to define, he said. “It’s like trying to describe why one would like the Mona Lisa. Prince kind of created the Minneapolis sound.”
– Prince suffered a fatal overdose in 2016 when he took fentanyl pills that were disguised as prescription Vicodin tablets. But after a two-year investigation, authorities in Minnesota say they haven't been able to uncover who provided the counterfeit pills and thus will not be filing criminal charges, reports the AP. "There is no reliable evidence showing how Prince obtained the counterfeit Vicodin containing fentaynl," said Carver County Attorney Mark Metz, per the Minneapolis Star Tribune. Nor is it clear whether Prince or any of his associates even knew he was taking fentanyl. "The bottom line is that we simply do not have sufficient evidence to charge anyone with a crime related to Prince's death," says Metz. That won't change unless new evidence or witnesses emerge, and a separate federal investigation into Prince's death is now similarly inactive. Just before the announcement, authorities said that Prince's doctor agreed to pay a $30,000 settlement in a separate allegation—that he prescribed painkillers in the name of Prince's bodyguard knowing they would be used by the entertainer himself. Dr. Michael Todd Schulenberg allegedly wrote the prescription for oxycodone under a false name to protect the singer's privacy, though his attorney disputed that assertion again Thursday and said her client settled to avoid legal costs and an uncertain outcome. (Prince's estate remains in limbo.)