When Bob Saget checked into room 962 at the Ritz-Carlton Orlando Grande Lakes in Florida on Jan. 7, the 65-year-old comedian seemed to have the vitality of a man half his age.

He was cracking jokes, waving to people in the lobby," a hotel employee tells PEOPLE in this week's issue.

"When people asked for selfies, he would run over and grab their phones to take the pictures with them, joking the whole time. He was a ball happy, positive energy."

But by the time the weekend was over, Saget was found dead in his hotel room bed on Jan. 9, raising many questions on how the beloved actor could have died so suddenly.

The mystery deepened when Chief Medical Examiner Joshua Stephany, MD later revealed in the autopsy that Saget's death was "the result of blunt head trauma," ruling the manner of his passing an accident not tied to any illicit drugs or toxins. Additionally, the comedian's autopsy indicated he had severe fractures to the back of his head and around his eyes when he died.

PEOPLE spoke with several involved in the investigation of Saget's death. "It's definitely an unusual case," an Orange County Sheriff's deputy says. "There are still a lot of unanswered questions."

The last time Saget was caught on surveillance video, he was seen exiting the elevator of the ninth floor and walking down the long hallway towards his room. 

Authorities who have seen the footage tell PEOPLE that nothing seemed out of the ordinary: Saget showed no sign of distress.