Cinda was last seen at the Oklahoma State Fairgrounds in Oklahoma City, Oklahoma on September 26, 1981. She was accompanied by her friend, Charlotte Kinsey. Charlotte called her family's home to announce that she and Cinda had been offered jobs assisting a worker unload plush toys from a truck at the fair. The girls' boyfriends said they left with a man who was 40 to 50 years old and wearing a yellow badge. The boys joined them and the man took them to a truck stop off Interstate 40, but the truck wasn't there. The man dropped them off in a parking lot, gave them $10, and told them to wait while he went to get the truck. He drove away with Charlotte and Cinda. Neither girl has been seen again.

After Charlotte and Cinda's disappearances, a yellow badge was found in the parking lot where they were last seen. It bore the name and photograph of a carnival drifter. The man was charged with the girls' abductions, but the charges were dropped a short time later. The suspect was able to prove he had been in Dallas, Texas the day Charlotte and Cinda disappeared.

Royal Russell Long, who was employed as carnie and part-time long-haul truck driver at the time, has long been considered the prime suspect in the girls' disappearances. Long was charged with kidnapping and murder charges for both Charlotte and Cinda in August of 1985. Long had been in Oklahoma City on the day the girls disappeared. Cinda and Charlotte's boyfriends identified Long as the man who offered the girls the jobs unloading toys. Long also had a history of sexual violence towards young women. His own daughter claimed he had molested her for years and witnessed him try to lure other girls with puppies or stuffed animals.

Authorities located the Pontiac Grand Prix Long had rented during his September 1981 stay in Oklahoma. Its make and model matched the vehicle a witness claimed to have seen Charlotte and Cinda riding in the day they disappeared with a man matching Long's description. Hairs that were found in the car's truck were analyzed using forensic testing and were matched to Cinda. Animal hairs were also located in the truck; those matched the types of dogs and a cat that Cinda had access towards before she disappeared. A lock of blonde hair found by investigators in Long's residence in Wyoming may have matched Charlotte's type; however, the test appeared to be inconclusive. Forensic tests proved that the mat in the truck of the Grand Prix had a bloody boot print as well as two bodies outlines in blood.

During court proceedings Long taunted the Pallett and Kinsey families, saying he was the only one who knew the truth. After the presiding judge threw out Long's daughter's testimony and much of the physical evidence, all charges against Long were dismissed. He is also a possible suspect in the disappearances of Deborah Meyer and Carlene Brown, who disappeared from Wyoming in 1974. He pleaded guilty to kidnapping in connection with the 1984 abduction of Sharon Baldeagle, who remains missing, and was sentenced to two terms of life in prison. He was still in custody when he died of a heart attack in 1993.

Cinda was a shortstop on a softball team at the time of her disappearance and was looking forward to trying out for the school basketball team. She had purchased tickets for a Van Halen concert which took place the week after she disappeared. Authorities believe the girls' bodies are still in Oklahoma, but may never found. Charlotte and Cinda's remain unsolved.