NEW YORK (CNN) -- There is little doubt of the trouble existing in Lisa and Craig Stebic's marriage, say friends, family and court documents.
Lisa Stebic's family says she petitioned the court to have her husband evicted the same day she disappeared.
Craig Stebic admits to filing for divorce just four months before his wife's disappearance.
They'd been in the midst of a tumultuous separation, while still living under the same roof. They had hardly spoken to one another in the last months before she vanished.
On the very day Lisa Stebic went missing -- April 30, 2007 -- she had petitioned the court to have her husband evicted from the family home, her family said.
It has now been a year and a half since the mother of two disappeared.
According to her husband, she left at 6 p.m., taking her cell phone and purse, while he was working in the backyard. Lisa Stebic often went jogging at the local track field around that time, but no one saw her that evening at the track.
Police say there has been no activity on her cell phone or credit cards.
For weeks afterward, police and search teams combed nearby areas, hoping to find the missing 37-year-old from Plainfield, Illinois.
The FBI joined in and divers searched bodies of water located near the Stebic home, but they have found nothing.
Police searched the Stebic home with a warrant in mid-May 2007. During the search, Craig Stebic was cooperative, allowing them access to the family computer and two vehicles, police said.
Police have not released the results of this search or investigation. But despite his cooperation with police, Stebic still refuses to take a voluntary polygraph and will not permit his children to be interviewed by police about their mother. While he has not been named a suspect in the disappearance of his wife, police say he is officially a person of interest.
Police did announce that they believe foul play was a likely factor in Stebic's disappearance, though they have not said what evidence leads them to that conclusion. They say that Craig Stebic's refusal to let anyone question his children has been impeding their investigation.
Lisa Stebic's parents and friends insist she would never go off on her own, leaving behind her children, who were 10 and 11 at the time. Even Craig Stebic says that he doesn't believe she would stay away this long voluntarily, especially from her children.
Craig Stebic and Lisa Stebic's family have been locked in a battle over visitation rights with the children in the last year, but finally last month a settlement agreement was reached. This gives hope to police and family that they might finally be able to question the children about the day their mother disappeared.
Craig Stebic maintains his innocence in the disappearance of his wife. His attorney, Dion Davi, says, "I don't understand why the police have named my client a person of interest. He has told police everything he knows about the day his wife disappeared."
Craig Stebic filed for sole custody of the children not long after his wife vanished. This request was denied by the court. Also, a few days after he was named a person of interest in his wife's disappearance, Stebic filed a motion to have their divorce proceedings dismissed. Stebic said his reason was that high legal bills adding up while they waited for news about his wife made a divorce proceeding impossible at the time.
Lisa Stebic's family and the Plainfield, Illinois, Police Department ask anyone having information on the whereabouts of Lisa Stebic to please call their tip line at 815-267-7217. They are offering a $75,000 reward. Stebic is described as being 5 feet 2 inches tall and 120 pounds with brown hair and brown eyes.