20 year old Elizabeth was a student at Central Texas College and attended classes before leaving for her part-time job at the 7-11 store on Rancier Avenue in Killeen, Texas on April 25, 1988. After work she went to a group study at her boyfriend's residence, about 30 miles away from her own home. She and her boyfriend got into an argument and she said she wanted to go home, and he refused to take her, so she left alone sometime between 9:30 and 11:00 p.m. Campbell never arrived home. Her family didn't realize she was missing until the next morning.

A clerk at another 7-11 store on Highway 190 in Copperas Cove, Texas reported seeing Campbell the night of her disappearance. The clerk said a man driving a light green Gremlin, whom she thought was a Central Texas College student, dropped her off. The 7-11 employees let her use their phone to call her boyfriend. She asked him to come and pick her up, but they got into another argument and Campbell decided to call her brother instead. This would have been a long-distance call and she didn't want to make it on the store's phone, so she went outside to use the pay phone. She has never been heard from again.

The next morning, when Campbell's parents couldn't find her, they attempted to report her missing. The police refused to accept a missing persons report until 72 hours had passed because Campbell was an adult. Her parents searched for her and investigated her disappearance on their own over the next three days.

Campbell's parents went to the Central Texas College campus and were able to locate the man who dropped her off at the 7-11. He said he had been working late at the college computer lab, saw Campbell walking down the service road and recognized her as a fellow student at the college. He offered her a ride to Copperas Cove, which was as far as he was going. The 7-11 where he dropped her off of was seventeen miles from her home.

Campbell's purse was located over 180 miles away, off Interstate 10 in Ozona, Texas, in 1992, four years after she was reported missing. Someone turned it in to the Crockett County Sheriff's Department, but they never recorded who had done this or when. The then-sheriff thought the purse had been turned in sometime between April 1988 and January 1989.

Authorities stated that there was no physical evidence relating to Campbell's disappearance inside the purse. It contained her Social Security card, military identification card and credit card, but her makeup, hair brush and keys were missing. Foul play is suspected in her case. Sometime after her disappearance, authorities released a sketch of a possible suspect; the sketch is posted with this case summary.

Campbell resided with her parents in Lampasas, Texas in 1988. She planned to transfer to Texas A&M University in the autumn of that year and study marine biology. Her mother described her as a very naive, trusting young woman.