The DuPage County coroner confirmed in a press release that they positively identified the remains were of the missing 50-year-old through dental records.
According to authorities, Cefolia's remains were found Friday in the Waterfall Glen Forest Preserve.
The coroner said the autopsy was performed the following day.
"A cause and manner of death have not been determined and remains under investigation," the coroner said.
In a news release, DuPage Forest Preserve Police Chief David Pederson said Cefolia was reported missing on August 8, 2020.
Officers received a call after contractors stumbled upon what appeared to be human remains, Pederson said.
Pederson said Cefolia was found hanging by a belt from a tree.
The chief said there were no signs of foul play.
His personal belongings, including his wallet, driver’s license, a backpack, and clothing he was wearing the day he went missing, were also found at the scene, Pederson said.
According to the Sun-Times, Cefolia had worked at United since 2007.