Indiana Jones wannabes aren’t just plagued by ancient curses of the treasures they pillage—some of them are haunted by their own guilt.

Last week, 20 years after a looter took ancient artifacts from an excavation site in Israel, the pieces were returned with a note. “These are two Roman ballista balls from Gamla, from a residential quarter at the foot of the summit,” the remorseful plunderer wrote. “I stole them in July 1995, and since then they have brought me nothing but trouble. Please, do not steal antiquities!”

The 2,000-year-old slingshot-style weapons were left in a bag at the courtyard of the Museum of Islamic and Near Eastern Cultures. They had originally been made by Romans to attack the city during the First Jewish-Roman War around 73 A.D. They had been missed by the archaeologists excavating the first-century city near the Syrian border, where 2,000 of the balls had been found, and stolen a few years after the site was closed. “We did not realize something was missing,” an archaeologist with the Israel Antiquities Authority said in a statement. “Such ‘returns’ are not that extraordinary. They happen every few years,” he told Live Science.