But, he says, that prescription is tangential to the case.
Dr. Michael Todd Schulenberg said he wrote an Oxycodone prescription for Prince under Johnson's name for privacy purposes, according to a search warrant that was among the documents unsealed.
The day before Prince died, his team called an eminent opioid addiction specialist in California seeking urgent help for the singer, an attorney working for the specialist and his son said.
April 16, 2016: Prince invites guests to a dance party at Paisley Park, where he plays "Chopsticks" on his new purple piano and shows off a metallic purple guitar.
The medical examiner's office said Prince died of an accidental overdose of the opioid fentanyl. Investigators interviewed Johnson sometime after Prince's death, and he told them Prince had gone to a local medical center for an illness in 2014 or 2015. Schulenberg had "put the prescription in Kirk Johnson's name for Prince's privacy".
-Cell tower data from Sprint, Verizon, AT&T and T-Mobile of all cell phones used at or near Prince's compound.
A prescription monitoring warrant, issued as part of the investigation, reveals the singer was never prescribed any of the controlled substances that were found at Paisley Park. A bodyguard carries Prince, who is unconscious, from the plane. Prince admitted that he had taken painkillers, according to search warrants.
On April 20, 2016, Johnson went to a Minnetonka Walgreens to pick up Prince's medication. He told investigators this was the first time he had ever done something like that for Prince.More news: Vettel wins Bahrain Grand Prix ahead of Hamilton
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A suitcase was discovered next to Prince's bed on the day he died and among the items inside, there were prescription pill bottles in Johnson's name - none of which were the medication prescribed by Schulenberg.
According to search warrants unsealed Monday, authorities searched Paisley Park, cellphone records of Prince's associates, and Prince's emails to try to determine where he got the fentanyl that killed him. The prescribing doctor was listed as Schulenberg.
April 17, 2017: Carver County authorities unseal 11 search warrant affidavits related to the investigation into Prince's death. Investigators believe "Peter Bravestrong" could have been an alias name for Prince that he would use when he would travel. The suitcase also contained lyrics for the song "U Got the Look" that appeared to be in Prince's handwriting.
Kornfeld, a pre-med student, was one of the three people who found Prince at his Paisley Park studio on April 21. Instead, he turned to emails, which he would access from an Apple Mac Book computer, under an account set up by his former manager.
It's been almost a year since Prince died of an accidental drug overdose, and his Paisley Park studio complex and home near Minneapolis is has become a museum and concert venue.
The unsealed documents confirmed reports from law enforcement sources a year ago that multiple prescription painkillers were found in Prince's home, belying his public reputation for living a clean and healthy vegan lifestyle.
TREATMENT PROGRAM: According to the court documents, Andrew Kornfeld was at Paisley Park when police arrived at the death scene, He had arrived in Minneapolis that morning to meet with Prince.