KANKAKEE, Ill. » Someone stole Abraham Lincoln’s hand.

The crime had no witnesses. There are no suspects. The police are not even certain when the hand disappeared.

About all anyone knows is that a plaster sculpture of the 16th president’s hand, proudly displayed for years at the Kankakee County Museum, has been missing from its shelf since at least Dec. 11.

Any art theft would be jarring in Kankakee, a working-class city about an hour’s drive south of Chicago, but because of its connection to Lincoln, the loss of this sculpture has touched a nerve here.

More than 150 years since the former Illinois legislator ascended to the presidency, Lincoln remains ubiquitous in this state. His face is on the license plates. Illinois calls itself the “Land of Lincoln.” And along the interstate near the Kankakee exit, a giant statue of Honest Abe greets passing motorists from the parking lot of an equipment rental company.

“Lincoln is a local treasure for us,” said Chief Larry Regnier of the Kankakee police, whose department is investigating the theft. So far, Regnier said, promising leads have been hard to come by.

Museum officials had thought that the theft might have been a prank, and that the plaster study would resurface in a few days. The police hoped someone might provide information about the theft after seeing a Facebook post by the department, which included photographs and described the hand as roughly “the size of a 8-10 pound ham.” The local newspaper, The Daily Journal, published an editorial pleading for the thief to come forward.

“We are blessed to have such a fine museum with an impressive inventory,” the editorial said, “but the collection is not complete without Lincoln’s hands.”

The hand was the work of George Grey Barnard, a sculptor who spent part of his boyhood in Kankakee around the time that Lincoln was assassinated, and whose admiration of Lincoln was a recurring theme in his art. The sculpture was displayed along with other renderings of Lincoln in a wing of the county historical museum built specifically to showcase Barnard’s work.

Connie Licon, the museum’s executive director, said the hand sculpture had been on display since at least 1991. This was the first art theft she said she could remember in more than 20 years at the museum.

“We were devastated. It just brought us all to the floor,” said Licon, who was alerted to the theft by a custodian who noticed the vacant spot on the shelf. “We’re a small museum, and we just don’t acquire pieces like this.”

The police report estimated its worth at $5,000, but described the artwork as “invaluable.”

“There’s almost no way to put a value on something like that because there’s no market,” said Jack Klasey, a longtime museum volunteer and local historian.

The theft occurred at the beginning of the museum’s busiest month. In December, groups of schoolchildren and others streamed through the museum — past the Barnard sculptures, tributes to local sports heroes and artifacts honoring three Kankakee County natives who served as Illinois governor — to admire Christmas trees decorated by civic groups.

“I saw it in the newspaper and just thought, ‘Who would go into that small museum and walk out with that hand?’” said Trisha Campbell, who stopped by with her co-workers days after the theft was discovered to browse the Gallery of Trees at the museum.

In addition to being outraged, museum visitors were perplexed. “I think it’s kind of crazy,” said Kelly Lambert, a college student whose aunt works at the museum. “Why would someone want to walk off with a fake Abraham Lincoln hand?”

Since the theft, Licon said curators had removed other small Barnard pieces from the display, fearing that they might also disappear. “Now we’re paranoid,” she said. “And we’re wondering: Is this person going to come back?”

There is a precedent for stealing Lincoln memorabilia, said James Cornelius, a curator at the Abraham Lincoln Presidential Library and Museum in Springfield, Illinois. In recent decades, Cornelius said, manuscripts and books with ties to Lincoln have been reported stolen. And more dramatically, in the 1870s, a band of criminals failed in an attempt to steal Lincoln’s body from his tomb in Springfield.

Many in Kankakee said they assumed that the hand thief lived in the city, and that the crime was more of an impulse than a well-planned heist.

Licon said she hoped the hand resurfaced soon.

“What makes people think what’s someone else’s belongs to them?” she asked. “Just return it in a quiet way. Just put it in a bag and leave it somewhere.”

© 2016 The New York Times Company