Authorities said the body of a missing Janesville woman was discovered under a stairwell in her home's basement and her boyfriend was arrested.

Janesville police officials said an autopsy on the body of 49-year-old Lisa Schaefer was taking place Wednesday to determine the specific cause of her death.

Deputy Police Chief Dan Davis said Schaefer's body was found Tuesday at her home in the 300 block of Parker Avenue. Davis said Schaefer's live-in boyfriend, 36-year-old Michael R. Paul, was arrested and tentatively charged with first degree reckless homicide and hiding a corpse. Davis said based on statements Paul made to officers, authorities are confident he was involved in the crimes.

Davis said when Schaefer was first reported missing by family members over the past weekend, officers visited her home and nothing appeared suspicious, nor was anyone arrested. Davis said the couple also lived with another man, who was out of the country at the time of Schaefer's disappearance.

Davis said shortly after the disappearance, information on social media sites raised police suspicions and ultimately led the investigation's focus to center on Paul.

Davis said there's no record of Janesville police involvement with the couple.

Neighbor Ruth Farrington told 27 News she noticed posters about Schaefer's disappearance appearing on her block. Farrington said she was new to the neighborhood and did not know Schaefer and did not make a connection between the missing person's posters and her neighbor. Farrington said she was planning to call a police detective when she found out the missing person's case had turned into a homicide.

"It is unnerving," said Farrington.

YWCA Executive Director Allison Hokinson said it does not appear officers missed anything obvious when they first went to the home and did interviews. But Hokinson said the fatality reinforces the need for continuing services to address domestic abuse, including a special domestic abuse response team involving YWCA social staff and Janesville police officers.

Paul is scheduled to make an initial court appearance on Thursday.

Schaefer worked at Janesville's Walmart. A family member declined comment on her death.