A man walked into a Michigan police station Tuesday and claimed to be an accomplice in the murder of a Detroit marketing executive found strangled in the backseat of her car.

Joseph Gentz, 48, allegedly said he had a direct role in the murder of Jane Bashara, who was found dead last Wednesday, and that the woman's husband was also involved in the crime, Fox affiliate WJBK-TV reported.

Bashara was found strangled inside her Mercedes-Benz in an alley on Detroit's East Side, about eight miles from the upscale Grosse Pointe Park home she shared with her husband and children. 

The 56-year-old's death was ruled a homicide by strangulation, and her husband, 54-year-old Bob Bashara, was named a "person of interest." He reported his wife missing last Tuesday night after she failed to return home.

The woman's coworkers reportedly said she was last seen Tuesday after a meeting at Detroit Edison's downtown headquarters. 

According to WJBK-TV, Gentz walked into the Grosse Pointe Park Police Department at about 4:30 a.m. local time Tuesday and told officers that the woman was murdered in her garage and that he helped dispose of her body.

Police can hold Gentz for up to 72 hours without arresting him. A Wayne County prosecutor said Tuesday that no warrants were submitted for any arrests in the case.

Bob Bashara failed a polygraph test administered Friday night, police said. The father of two hired well-known defense attorney David Griem, who spoke to reporters after Jane Bashara's funeral Tuesday morning.

He described Gentz as "very questionable" and added that Bob Bashara identified Gentz as someone who may have had it in for the family -- and put him on a list of people that police should look at.

Gentz' neighbors at the apartment where he used to live in the St. Clair Shores suburb of Detroit described him as "big and angry."

"He broke into the apartment above me twice," former neighbor Glenda Southerland told the station. 

"He was squatting here threatening my life," added the apartment's manager, Kellie Roddy.

Bob Bashara's sister, meanwhile, insisted Sunday that he is "an innocent man" and "incapable of this horrific act."

Newscore contributed to this report. 

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Jane Bashara Murder: Sources Say Possible 'Accomplice' in Custody: MyFoxDETROIT.com