LOUISVILLE (WHAS11) -- A former FBI employee pleaded guilty to obstruction of justice when she lied and misled investigators who were investigating the disappearance and eventual death of a Southern Indiana woman in late 2016, federal records show.

Belenda Sandy could spend up to 20 years in federal prison when she is sentenced.

In the plea agreement she signed, Sandy admitted she lied to Florida investigators--who were working with the FBI--about having had contact with Jarvis Madison, who was suspected in the disappearance of his estranged wife, Rachael.

According to police, Rachael Madison left Clark County, Ind. November 14 after filing a report with Indiana State Police claiming her husband held her against her will in his vehicle. She said he was armed with a handgun and threatened to kill her if she tried to get away.

On November 27, an investigator wrote in the plea agreement, Rachael Madison went for a jog on the beach in Ormond Beach, Fla. Investigators said shortly after that jog is when Jarvis Madison shot and killed her.

That same day, investigators revealed, Jarvis Madison called a phone number associated with Sandy and held a 23-minute conversation.

"Sandy specifically denied having the 23-minute conversation with Madison on November 27, 2016, despite the investigator telling her that the call was reflected in telephone records," the agreement notes.

The document said Sandy changed her story the next day, claiming she admitted Madison did, in fact, call her the previous day, but that while he was talking, she laid the phone down and did not pay attention.

Investigators, according to the records, later learned Sandy did not tell them Madison stayed at her home from November 17 to November 26, provided him money and that during that 23-minute phone call, Madison told Sandy he was looking for his wife.

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"Had Sandy been truthful with the VCSO Investigator about Madison's conduct, both before and after the victim's disappearance, the VCSO would have immediately notified local FBI Special Agents that the victim was likely kidnapped by Madison and taken to another state."

Investigators arrested Jarvis Madison in Kentucky on December 2 and that same day, according to a criminal complaint, he led investigators to her partially buried remains in Tennessee after confessing to fatally shooting her three times.

The FBI said a search of his cell phone revealed he took pictures of Rachael's lifeless body after killing her.

Investigators said Sandy's deception prevented them from potentially arresting Jarvis Madison with his wife's body still in his vehicle.

A date for Sandy's sentencing was not immediately available.