Investigators said new leads in the case led to the dig inside a home in southwest suburban Joliet.
Illinois State Police, the FBI and crime scene investigators unearthed a portion of a residential concrete basement slab in the 100 block of South Margaret Street in Joliet.
Investigators won't say if they found anything of significance inside the home Thursday.
Jody Abrams Walsh, the victim's sister, said she was notified by state police Thursday morning about the new leads in her sister's case.
"I am in a state of shock," said Abrams Walsh said.
Crime scene investigators spent the day digging in the basement of a home on South Margaret Street in Joliet.
"The people that did this to her get to go to their birthdays, anniversaries, and everything, and live out their lives like nothing happened. Something happened. They murdered my sister," Abrams Walsh said.
Abrams was last seen at a Joliet gas station filling up her red Dodge Daytona. Her father filed a missing persons report after her car was found abandoned in south suburban Harvey. Her purse was discovered a few blocks from her car shortly after her disappearance.
At the time of her disappearance, Abrams was suing several members of the Will County Sheriff's Department after being fired from her job as a deputy.
Court papers allege she had an affair with a Will County Sheriff's officials, and that she was fired "to prevent plaintiff from discussing the facts of the relationship."
Her relatives said she'd been harassed for years.
"She had her car broken into, tires slashed, on and on," her sister said.
The victim's family says this isn't the first time investigators have looked at this house.
"A dog hit on this. All we were told -- this was when mom and dad were alive -- they said nothing has come out of it. But we did not get to talk to any of the investigators or hear any of the reports. Nothing because it is an ongoing investigation," said Abrams Walsh.
Her loved ones are hoping this time they finally get answers after almost 27 years.
"She's my sister, our sister. She's got nieces and nephews, great-nieces and great-nephews," her sister said.
Police said the people who live at the house are not connected to the investigation.
"It's very, very surreal, that you know, that this could be happening right here in the neighborhood. I mean, this is very I raised my children, so, and never had any reason to believe that anything out of the ordinary ever went on here," said neighbor Sue Sullivan.
"It's pretty quiet, nothing really goes on here. You don't really like see anything like this around here, since I've lived here, everything's pretty quiet," said neighbor Doris Magana.