Richard E. Aaron/Redferns(ST. PAUL, Minn.) — No criminal charges will be brought in the accidental drug overdose death of Prince, federal prosecutors said on Thursday.Prosecutors also announced that Michael T. Schulenberg, the Minnesota doctor who prescribed an opioid painkiller for Prince a week before the musician’s death in 2016, has agreed to pay $30,000 to settle civil charges that he wrote an illegal prescription. Prince died of an accidental fentanyl overdose in his Paisley Park estate on April 21, 2016.Carver County Attorney Mark Metz told reporters Thursday that Prince thought he was taking Vicodin to manage pain but unknowingly took counterfeit pills laced with fentanyl.“Prince had no idea he was taking a counterfeit pill that could kill him,” Metz said.Despite “intensive” investigation, Metz said law enforcement was unable to determine who provided the counterfeit Vicodin laced with fentanyl that killed Prince.Dr. Michael T. Schulenberg, who denies any liability, violated the Controlled Substances Act when he illegally wrote a prescription for Prince in someone else’s name, federal prosecutors said Thursday in official settlement documents obtained by ABC News.“Dr. Schulenberg prescribed Schedule 2 controlled substances in the name of an individual knowing that the controlled substances were intended to be used by another individual,” U.S. Attorney Greg Brooker said. “As licensed professionals, doctors are held to a high level of accountability in their prescribing practices, especially when it comes to highly addictive painkillers.”Schulenberg agreed to settle the civil charges by paying $30,000 and submitting to monitoring by the Drug Enforcement Administration.“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,” DEA Minneapolis-St. Paul Division Assistant Special Agent in Charge Kenneth Solek said.The settlement is “neither an admission of facts nor liability by Dr. Schulenberg,” court records said. Prosecutors also affirmed in a separate letter to Schulenberg’s attorneys that the doctor is not a target of a federal criminal investigation.“Dr. Schulenberg decided to settle with the United States regarding alleged civil claims in order to avoid the expense, delay and unknown outcome of litigation. He made no admission of facts nor liability and denies any such liability. The United States Attorneys’ Office for the District of Minnesota has confirmed that he is not a target in any criminal inquiry, and there have been no allegations made by the government that Dr. Schulenberg had any role in Prince’s death,” Schulenberg’s attorney, Amy Conners, said in a statement to ABC News. “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.”Copyright © 2018, ABC Radio. All rights reserved.