Madison and her friend, Susan Smalley, planned to spend the night of March 19, 1988 at the Smalley family residence in Carrollton, Texas. It has been established that the girls were at the house at approximately 12:00 a.m. on March 20, as Madison called a friend from their home at that time. Smalley and Madison departed together afterwards. They were traveling in Madison's 1967 Mustang convertible. The car had been painted green and gold, the colors of Newman Smith High School, where the girls were seniors at the time. A photo of the car before it was painted is posted below this case summary. Madison worked for a local allergist and she planned to attend college. She took the SAT test the morning before her disappearance.

Two young women matching the descriptions of Smalley and Madison attempted to purchase beer at a local 7-11 convenience store in the early morning hours of March 20. They were refused service due to their ages. Smalley and Madison were seen at to the Steak and Ale in Carrollton afterward; Smalley was there employed as a hostess. One of her co-workers told investigators that Smalley spent approximately five minutes inside the restaurant speaking to a friend, then departed. Madison stayed inside the vehicle while Smalley was in the establishment. This was the last confirmed sighting of the girls.

Smalley's mother called authorities when she noticed that neither of the girls was in the family's home later in the morning. Madison's convertible was located later in a strip mall parking lot in Dallas, Texas on Forest Lane and Webb Chapel Road. The vehicle was locked and appeared to be undisturbed; Madison's portable stereo was placed on the back seat.

Madison's boyfriend, Kevin R. Elrod, is considered a possible suspect in the females' disappearances. He was allegedly abusive to her, and she had been trying to end the relationship before her disappearance. Elrod began dating another woman shortly after Madison vanished, and told her he'd killed Madison and Smalley and buried them in a cemetery outside of Carrolton. The witness went to the police with the story and they located and searched the cemetery indicated, but found no evidence of a crime. Elrod didn't deny making the confession, but he recanted it immediately and later passed a polygraph about the case. He later moved out of state and changed his name.

Smalley and Madison's loved ones never believed they ran away. They described both of them as responsible teenagers who got excellent grades and were always good at keeping their families notified of their whereabouts. Foul play is suspected in the girls' disappearances. Their cases remain unsolved.

The author Shawn Sutherland published a book about the case, called This Night Wounds Time, in 2009.

Above: Madison's car