Gentz, a St. Clair Shores handyman, said Bob Bashara—the husband of Jane Bashara—promised Gentz money and threatened him.
The guilty plea means Gentz could serve between 17-28 years in prison. His sentencing trial will take place Jan. 29, 2013, according to WXYZ.
Maria Miller, a spokesperson for the Wayne County Prosecutor's Office, said the investigation into Jane Bashara's death is still open.
"The Jane Bashara homicide case remains under investigation," Miller said in an email. "No other charges are expected at this time."
Gentz’s plea is the latest in a case that has stunned the Grosse Pointe community.
Bob Bashara pleaded guilty to solicitation of murder in October, telling the court he tried to hire a hitman to kill Gentz. He was sentenced to 6-20 years in prison on Dec. 10.