Anne Swaney died from "asphyxia due to compression of the neck area, throttling (manual strangulation) and blunt force traumatic injuries to the head and neck region," according to the autopsy. Her body was found floating face-down in the Mopan River on Friday morning about a quarter of a mile from where she was staying.
Swaney, 39, was the executive producer of online operations at WLS-TV, where she had worked since 1999.
While police said most of her belongings were recovered, her family told WLS-TV her cellphone appeared to be missing. Her belongings will be delivered to U.S. Embassy officials Monday, WLS-TV reported.
"At about 3 o'clock we realized she wasn't around and that's when we were alerted that her things were down at the yoga platform," Santiago Juan, who owns the eco-resort where Swaney stayed, told WLS-TV.
Police detained a man fishing near where Swaney's body but stopped short of calling him a suspect.
"He is a person of interest," said Rafael Martinez, a spokesman for the Belize Ministry of National Security. "He is a person who the police believe can assist in the investigation."
Martinez said the investigation was complicated by the river in which her body was found is a mile from the Guatemalan border.
"It's not far-fetched to have someone come and commit a crime in Belize City or Belize and go across the border into Guatemala," Martinez said.
Her colleagues remembered her as a world traveler who gave her whole heart to what she loved.
"I'm really without words because it is a tragic loss for our newsroom, and really for the entire station and for the city of Chicago. She was terrific at what she did," ABC7 Chicago President and General Manager John Idler said.
"She was a trailblazer in the digital news space and was one of our first website employees," said John H. Idler, president and general manager of ABC7. "Anne helped us evolve our business and our newsroom, but most importantly, she was a kind person who was always had a smile and a positive attitude."
"Anne was our leader, Anne was our conscience. Anne wanted to make sure that every story that we put online was first and foremost right," said Kevin Carpenter, director of digital operations at ABC7 Chicago. "There's always going to be a spot there that we will miss."