His remains were found Jan. 28 after days of digging in the woods on the Plant City, Fla., property and after heavy equipment had been brought in to break through a large piece of concrete. An autopsy the next day confirmed that the body was that of Shakespeare. The identity was determined through fingerprints, the sheriff's office said.
Authorities have not said where the tip came from or even when it came in.
Hillsborough County Sheriff's Office spokeswoman Debbie Carter declined to comment on what exactly was found in the grave, only that it was clear the body had been there for a while.
Moore, who befriended Shakespeare in early 2009, when his millions were dwindling, had said throughout the investigation that she only helped Shakespeare vanish to get away from people asking him for loans.
"I wish, I hate to say this, but I wish I did a lot of things differently, but I've never did anything unethically, unprofessional, or anything he did not want done," Moore said this week. "Everything he wanted done, all that stuff that they keep bringing out, that has, all has witnesses to back it up.
Moore had made several attempts to make it look as if Shakespeare had been communicating with his family -- offering someone a $200,000 house in exchange for reporting a false sighting, sending his son $5,000 in cash for his birthday and sending text messages -- even though Shakespeare had already disappeared, Polk County authorities said.
In February 2009, two months before Shakespeare was last confirmed to have been seen, Moore opened up a limited-liability account with his money and gave herself signing authority, according to the Polk County Sheriff's Office. She then rewarded herself with $1 million, which she spent on a Corvette, a Hummer and lavish vacations.
The only previous arrest that had any connection to the case came in late January when Polk County authorities arrested Lakeland police officer Troy McKay Young, charging him with providing Moore with confidential information from law enforcement databases in exchange for compensation.
The Associated Press contributed to this report.