Criminal justice experts say the pace of the investigation doesn't necessarily mean it's in trouble or that no one will be charged.
Six witnesses at the scene told investigators that Prince "had a history of going through withdrawals, which are believed to be the result of the abuse of prescription medication", according to an affidavit. They say it's a complex thing to track illegally obtained pills, and investigators and prosecutors want to build strong cases before interviewing witnesses who might provide useful information.
Summary: Unsealed court documents show that Prince's home was filled with concealed prescription drugs issued to his longtime friend Kirk Johnson.
The search warrant notes a "sizable amount of narcotic medications located inside Paisley Park" - not just in one area but throughout the residence and in areas where Prince would commonly frequent - his bedroom, wardrobe and laundry room.
The newly-released search warrants list a Bayer Aspirin bottle with 64 and-a-half pills with the label Watson 853.
Many of Prince's custom-made outfits - about 6,000 pieces of clothing and 1,000 pairs of shoes - were on display, while visitors were also allowed to take a look at his gold records and awards while the NPG Music Club is where Prince entertained friends and performed intimate gigs for small groups.
Many pills were inside a suitcase with the name tag "Peter Bravestrong" - an alias used by the singer.
In a statement Monday, Schulenberg's attorney denied he had ever directly prescribed opioids to Prince.
"Dr. Schulenberg met with Prince and prescribed him Clonidine, Hydroxyzine Pamoate and Diazepam".
Prince was found dead in the elevator of his home in Chanhassen, Minnesota, by Mr Johnson on 21 April previous year. It was known as a hydrocodone-acetaminophen and was one of the prescriptions given by his doctor.
The investigation into the singer's death is ongoing.
Search warrants and affidavits from the Carver County Sheriff's Office, which is investigating Prince's death, were unsealed on Monday.
Dr. Michael Schulenberg admitted to cops that he prescribed Oxycodone for Prince the same day he overdosed on a jet on the way home from Atlanta (April 14, 2016), forcing an emergency landing and a shot of the reversing agent naloxone to counteract the effects of the drug. According to the unsealed search warrants, investigators did not find fentanyl in Prince's house, however.
Investigators also said Prince got painkillers through other people.
The specialist, Dr. Howard Kornfeld, couldn't get there immediately so he sent his son, Andrew Kornfeld, on an overnight flight to Minnesota.
Investigators report that statements provided by those at Paisley Park when the warrant was served were not consistent and were sometimes contradictory, especially some statements made by Kirk Johnson. He and five others were searching for Prince when Kornfeld said he heard a scream. He was found dead inside of an elevator at his home in Minnesota, and an autopsy showed that he had passed due to an accidental overdose.
Laws against prescribing with a false name are not usually enforced when a doctor intends to protect a celebrity's privacy, said Los Angeles attorney Ellyn Garofalo.
Prince's body was later cremated.