(CNN) Orlando, Florida, police have closed their investigation into the shooting death of singer Christina Grimmie, and while it reveals little about the shooter's motive, several of his coworkers felt Kevin Loibl was obsessed with "The Voice" singer.

The police department's report on the case is filled with curiosities. Among them: Loibl's family said he had no history of mental illness but lived "like a hermit" and covered his bedroom windows with aluminum foil and heavy curtains because of "an aversion to light."

And though Loibl had no criminal record, St. Petersburg police responded to the family's home in 2014 because of a domestic disturbance involving Kevin Loibl and his father's girlfriend, the report says.

As for the two guns Loibl had in his possession following the murder-suicide, the report says the 27-year-old purchased them legally days before he gunned down Grimmie as she signed autographs following one of her shows.

OPD can confirm 27 year old Kevin James Loibl, suspect who shot Christina Grimmie, is from St Petersburg, FL pic.twitter.com/iN6RUi3VRx — Orlando Police (@OrlandoPolice) June 11, 2016

In both cases, he bought the guns -- different models of Glock 9 mm handguns -- and picked them up after five-day waiting periods, the first on May 31 and the second on June 7 -- three days before he gunned her down.

Other telling facts from the investigation:

Hotel clerk felt Loibl was 'strange'

Police have closed the probe into Grimmie's death.

When police examined his body, they found two handgun magazines in his pocket, a tactical knife strapped to his ankle, a Florida driver's license, a ticket for Grimmie's show, which he'd printed five days prior and a hotel key for a room at the Courtyard by Marriott in Orlando.

Police showed the front desk manager a photo of Loible and he "instantly" asked if this was a suspect in the Grimmie shooting. The manager said Loibl had checked in the night before the concert, arriving by cab about 1:30 p.m., and struck the manager as "strange." Loibl had no luggage and paid $269 for the room.

"There was no luggage; no personal belongings visible and the bed looked as if he slept on top of the covers. In the trash it appeared he had purchased some food from the hotel snack bar and ate it in his room," the report says.

Phone encrypted, computer not working

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Loibl's father and brother said he rarely left his room except to go to Best Buy, where he had worked part time, mostly on weekends. Neither had ever heard Loibl mention Grimmie and they never saw him watch "The Voice." They never saw him with a gun, either. Loibl did, however, "spend a great deal of time on his computer in his room," they told an investigator.

In searching his room, police found a flyer for a burial service that said it would "spread your remains around the base of a tree" -- an identical flyer was found on Loibl at the shooting scene -- but they found no documents or photos related to Grimmie.

Later, a detective learned Loibl's phone was encrypted, stopping police from extracting any data. Also, his computer was not working, "and it appeared Loibl had intentionally destroyed the hard drive." Police found no threatening emails or texts on Grimmie's phone, and it did not appear the two had ever been in contact.

'Only friend': Loibl was obsessed

Cory Dennington, who knew Loibl for 15 years and believes he was his "only friend in the world," told police that Loibl had become fixated on Grimmie in the last six months to a year. Loible told him "he watched everything having to do with her."

Dennington believed Loibl "spent most of his waking hours watching Christina on YouTube as well as constantly monitoring her social media accounts. Despite following her on social media, Loibl himself did not have a Facebook, Twitter, or any other social media account," the report says.

Loibl claimed to be an atheist, but told Dennington that Grimmie's Christianity had spurred a change of heart and "helped him to see the world in a different way." If there was a God, Dennington recalled Loibl telling him, and "he has seen it in her."

Many who knew Loibl noticed changes in him prior to the slaying -- he lost 50 pounds, underwent Lasik surgery, had his teeth whitened and got hair implants -- and Dennington told police that Loibl said he had done it all for Grimmie.

Obsession endangered friendship

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About two months before Grimmie's killing, Dennington began to realize Loibl's obsession with the 22-year-old singer wasn't healthy or normal, he told police.

He said he tried to explain to Loibl that it was illogical to believe he could have a relationship with Grimmie. When he did so, "Loibl would become angry and defensive."

"He said Loibl would not entertain the idea that his plan would not work and when Dennington did, he threatened to end their friendship. Loibl never elaborated on what he would do if he met Christina, but he referred to her as his 'soul mate,'" the report says.

The two men last spoke five days before the show. They were at work, and Loibl returned some magazines he had borrowed months before and said, "I love you, brother." He also said he "was tired and ready to ascend," Dennington recalled for police.

In hindsight, Dennington said, Loibl was saying things he now regards as weird and sad. But he never heard Loibl talk about guns or threaten to hurt himself or Grimmie.

Coworkers knew of infatuation

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Loibl's Best Buy supervisor, Luke Dahl, described Loibl as "socially awkward, detached" and said he had no social skills. Loibl worked "in the back" of the store, where he did not interact with customers.

Dahl never heard Loibl mention Grimmie, but Dennington -- who also worked at the store -- mentioned the matter to Dahl in January or February, saying their friendship was in jeopardy because of Loibl's "unrealistic infatuation with Christina Grimmie," the supervisor said. Dahl never spoke with Loibl about Dennington's concerns, but did later observe him watching YouTube videos of Grimmie at his work station.

At least five of Loibl's coworkers told police they knew of his obsession with Grimmie, but they didn't realize the extent of it. And though his physical changes were apparent, they didn't notice any mental changes. Dennington said Loibl's colleagues "would good naturedly tease Loibl about his 'internet crush,' " the report says.

One coworker recalled Loibl boasting to her that he had played online games with Grimmie, but police were unable to confirm the claim.