Today, the FBI—along with Boston’s Isabella Stewart Gardner Museum and the U.S. Attorney’s Office in Massachusetts—asked for the public’s help in recovering artwork stolen from the museum more than two decades ago in what remains the largest property crime in U.S. history.

At a press conference this afternoon in Boston on the 23rd anniversary of the theft, officials hoped to get the attention of those who might have or know the whereabouts of the 13 stolen works of art—including rare paintings by Rembrandt and Vermeer—by publicly restating a $5 million reward.

“Today, we are pleased to announce that the FBI has made significant investigative progress in the search for the stolen art from the Isabella Stewart Gardner Museum,” said Richard DesLauriers, special agent in charge of the FBI’s Boston Field Office. “We’ve determined in the years after the theft that the art was transported to the Connecticut and Philadelphia regions. But we haven’t identified where the art is right now, and that’s why we are asking the public for help.”

“With these considerable developments in the investigation over the last couple of years,” said Special Agent Geoff Kelly, who heads the FBI investigation, “it’s likely over time someone has seen the art hanging on a wall, placed above a mantel, or stored in an attic. We want that person to call the FBI.”