Despite the efforts of the Commercial Crimes Division of the Los Angeles Police Department and the F.B.I., the case went cold not long after the theft was discovered.

Until recently.

On Sept. 25, Detective Steven Franssen of the Commercial Crimes Division got a call from a police station in San Fernando, Calif. He was told that a woman had showed up with the prints in her car and wanted to turn them over to the authorities.

“This is not normal,” Detective Franssen said in an interview.

The woman, whose name was not released, said she had found over 1,300 prints in a pile of items she inherited a few years ago from a deceased relative, Detective Franssen said. She said she had taken them home and forgotten about them.

It was only a few weeks ago, Detective Franssen said, that the woman decided to go through the items and noticed the art. In doing a Google search to learn the value of the works, the woman discovered that the prints were listed as stolen, she told the police. She immediately loaded them into her car and drove to her local police station.

It is unclear how the woman’s relative obtained the prints. She told the detective that her family member was gifted the art, but she did not know from whom.