Ms Bills, who went missing last month, was connected to the body that was found through tattoo markers after it was discovered in Alpena Township on Tuesday, according to Michigan State Police.
An autopsy will attempt to establish the cause of death.
Ms Bills was last seen on 1 August in Alpena. Investigators said that an anonymous tip prompted them to look for Ms Bills at a home on Naylor Road, where they found the body.
“The tip led us to an area where we had seen that there was some fresh dirt and something that looked like it had been dug up recently,” First Lieutenant John Grimshaw said at a press briefing, selon Fox News. “So it was easy to locate, there were several spots on the property like that, so we narrowed our search to those and that’s where we found the body.”
“It took us a long time to find the remains and to get her out of there," il ajouta.
Police said the home where the body was found belongs to Joshua Wirgau, 34 – a person of interest in the death of Ms Bills. Mr Wirgau was not at the home when police searched the property.
Following an unrelated incident that took place earlier this week, Mr Wirgau was already in custody on charges of unlawful imprisonment and felonious assault.
Police said Mr Wirgau has a lawyer.
Since the investigation was ongoing, further information wasn’t immediately available.