Brooks was last seen in her hometown of Fredericktown, Missouri on August 5, 1989. She came home at 10:00 p.m. after seeing her brother's baseball game. A short time later, Brooks said she was going for a ride on her ten-speed girls' bicycle. She never returned. Her disappearance was reported at 2:00 a.m.

Brooks was seen standing near her church when a battered light gray, green or blue station wagon with Missouri license plates pulled up and the driver spoke to her. She got back on her bike and turned south on Mine La Motte. Later, some witnesses including Brooks's boyfriend heard a scream of "help me!" in the neighborhood. A vehicle was seen turning left on Franklin and driving towards Highway 67. Brooks's bicycle was found abandoned on a residential lawn on High Street, five blocks from her home, later in the evening. There was no sign of Brooks and she has not been seen again.

Three men were implicated in Brooks's disappearance in 1998. Nathan D. "Danny" Williams was charged with Brooks's murder in 1999. Investigators stated that Williams was identified by a witness as the man who was seated in the back of the station wagon with Brooks the night she was abducted. Witnesses also identified Bryant Squires as the driver of the station wagon; he has since died of cancer and AIDS-related complications. He allegedly made a deathbed statement to nurses implicating Williams and himself in Brooks's abduction and murder and in other crimes.

Timothy R. Bellew, a friend of both Williams and Squires, was initially implicated in Brooks's disappearance as well. Bellew admitted he lied to Federal Bureau Of Investigation (FBI) agents about the location of Brooks's remains. Bellew claimed Brooks was buried in an abandoned meat freezer on his father's 96-acre property, but extensive searches of the area through 2001 have not produced any evidence.

Williams pleaded not guilty to the first-degree murder charge against him in 1999. Authorities believe that he was the person responsible for killing Brooks in 1989 by slitting her throat, and Squires and Bellew helped him cover up the crime. Both Williams and Bellew have records of sex offenses and other crimes. Bellew was charged with second-degree murder in Brooks's case.

The murder charge against Bellew was dropped for lack of evidence in 1999, and he was charged instead with lying to investigators about where Brooks's body was buried. He pleaded guilty and was sentenced to 30 months in prison. In 2003, the murder charge against Williams was also dropped. Authorities still believe the men were involved in Brooks's presumed murder, but stated there is not enough evidence to convict them at trial. Williams had also been charged in the 1975 murder of a young woman; that charge was also dropped for lack of evidence in 1998, ten days before the trial was set to begin. Williams is still in prison for an unrelated rape conviction.

Brooks has never been located.