The Marathon County Sheriff's Department said Wednesday that a 27-year-old woman who reportedly fell out the passenger door of a pickup truck her boyfriend was driving died from severe trauma to the head.
Chief Deputy Scott Parks said an autopsy of Catherine Borchardt found injuries "consistent with the story of her falling out of a motor vehicle. There were some abrasions and contusions that were the result of sliding across the pavement."
The investigation continues, including an inspection of the pickup truck, Parks said. There is no evidence the woman had been run over, he said.
The boyfriend, Brandon Bender, 27, is jailed on $25,000 bond after being charged with driving under the influence of a controlled substance causing injury.
Authorities say Borchardt was seriously injured in the incident early Sunday morning. On Tuesday, she was pronounced dead.
A criminal complaint shows Bender admitted to Marathon County Sheriff's officials that he had been drinking and smoked marijuana.
Marathon County Sheriff's officials said Bender told them he was driving in Elderon, when Borchardt fell out of his truck.
The Marathon County District Attorney's office said it is working closely with the Marathon County Sheriff's Department.
"They definitely want to do a thorough investigation to understand exactly what happened, what the events of that evening were, to confirm through evidence, anything that they can find," said Marathon County Deputy District Attorney Theresa Wetzsteon.
Court records show Bender originally told officials it was his girlfriend who was driving. It goes onto say Bender claimed he woke up and realized she had fallen out.
But after an initial investigation, authorities determined that was not the case. They said that's when Bender's story changed.
"This is obviously very significant to Ms. Borchardt's family, very significant to Mr. Bender, very significant to the community. We want to make sure that we know all that we can, so we make the right decision,"said Wetzsteon.
Bender was initially charged with causing injury while driving under the influence, but now that his girlfriend has died, Wetzsteon said that will change.
"The unfortunate and tragic death of Ms. Borchardt obviously changes the charge from causing injury, to OWI related homicide,"said Wetzsteon.
Authorities say Bender's blood alcohol content was 0.06 percent. That is under the legal limit.
Bender does not have an attorney listed. Bender is set to appear in court again later this month.