Stevenson and a friend, Peggy Rahn, were last seen in Pompano Beach, Florida on December 29, 1969. They had gone to the beach separately; a family friend took Rahn and Stevenson went with her uncle. The girls met at the beach by chance and began playing together. They both attended Palmview Elementary School and had mutual friends, but they didn't know each other well prior to that day.

At 1:00 p.m., Rahn and Stevenson decided to walk to the parking lot to buy ice cream. A convenience store clerk reported seeing a man buying ice cream cones for Rahn and Stevenson. He identified the girls from photographs and described their companion as a Caucasian man in his twenties, about six feet tall and 200 pounds, with sandy-colored hair, gray eyes and a humped nose. Rahn and Stevenson have never been heard from again.

Authorities initially suspected both girls had drowned. However, nobody saw them in distress in the water that day, their bodies were not recovered, and Stevenson was known to be a good swimmer. The drowning theory was eventually discarded as implausible. The man who took Rahn to the beach was questioned as a possible suspect. He cooperated with the investigation, passed a polygraph, and was ruled out in the investigation.

The serial killer Gerard John Schaefer Jr. is believed to have been responsible for the children's disappearances. A photograph of him is posted below this case summary. Schaefer a suspect in the deaths and disappearances of dozens of girls and young women, including Nancy Leichner, Pamela Nater and Carmen Hallock. The family of Debora Lowe, who disappeared in 1972, believes he was involved in her case as well. Schaefer was only convicted of two murders.

Prosecutors publicly accused Schaefer of killing Rahn and Stevenson in 1973. He denied it at that time, but in 1989 he wrote a letter and confessed to murdering the girls. He was never charged in their cases, however, and was himself murdered in prison in 1995.

Stevenson and Rahn's bodies have never been located.

Above: Schaefer