BELOIT, Wis. -- Beloit police confirmed they have questioned an ex-boyfriend of a Janesville woman found dead in a downtown Beloit business.

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Police refused to call the man a suspect in the homicide investigation, but they haven't ruled out talking to him again.

Julienne McGuire, 44, was found dead Monday morning. She opened the Edward Jones office building in downtown Beloit at 8 a.m. A co-worker found her dead around 9:30 a.m. An autopsy is scheduled to be performed on McGuire on Tuesday afternoon.

Police won't release information on how or why McGuire was killed, saying it may hurt the investigation.

“We aren't saying anything about cause of death because that would lead to a motive, which is information that we need to keep close to our detectives when they interview people or actually interrogate them,” said Beloit Police Chief Norm Jacobs.

McGuire had a restraining order issued last year against an ex-boyfriend. He was questioned in the presence of his attorney.

“He gave us some information that will help us with the case,” said Jacobs. “And we haven't decided he's a suspect. And we may or may not talk with him again.” The office was back open Tuesday. Co-workers told News 3 they are puzzled by the shocking murder.

“Can you imagine? You know something like this happening right across the street and never hearing a word? It's really sad,” said Beloit resident Cindy Thomas.

Police say it's especially hard because many people who live and work in Beloit knew McGuire.

“People would walk by the business and wave or knock on the window going in,” said Jacobs. “They know who she was. And they're very concerned."

Police told News 3 the murder was an isolated incident, but they wouldn't say if they believe McGuire knew her attacker.

Citizen tips have yielded many leads, WISC-TV reported. Beloit police are asking again for anyone working in the downtown Beloit area with information on any suspicious activity to call (608) 364-6800.

McGuire told the Janesville Gazette last year that she feared for her life after her ex-boyfriend was arrested for stalking her. The man tells the Gazette he has an alibi.

Meanwhile, police continue the search for two big pieces of evidence: a murder weapon and McGuire’s purse.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.