The cameras were looking the other way when a thief stepped up to a display case inside the Loudoun County courthouse last week, jimmied open its glass lid and stole a collection of historic coins.

The 25 sheriff's deputies who patrol the courthouse every day were busy with other duties when the bandit carefully removed some adhesive and took the 14 pennies and dimes, including a piece from colonial times that authorities say is worth as much as $5,000.

"This was very bold," acknowledged Kraig Troxell, the spokesman for the Loudoun sheriff.

The coins, which mostly dated to the 19th and early 20th centuries, were excavated from the courthouse lawn in 1997 by archaeologists in preparation for a renovation of the historic Leesburg building. Authorities identified one piece as a King George III penny -- a coin that would have circulated in the middle to late 1700s, during the last years of British rule in Virginia.

The set was displayed in one of two cases in a public hallway, along with other artifacts unearthed during the archaeological dig, including pottery shards and a Civil War-era belt buckle and bullet. But only the coins disappeared.

The theft was discovered by a court patron who spent time admiring them Tuesday morning and was so intrigued that he brought his child over to take a look Wednesday morning. Noticing the coins gone, he alerted authorities, said Loudoun Circuit Court Judge Thomas D. Horne.

Investigators have very little to go on.

The crew responsible for courthouse security leaves at night -- a deputy said the last officer left at 5:45 p.m. Tuesday. But the officers sweep the building to ensure it is empty before they lock up. Troxell said investigators, therefore, theorize that the theft occurred in broad daylight, while court was in session.

There is a camera affixed to the ceiling a few yards from the display cases, but it has been no help. It provides a live feed for deputies and has no tape to review, Troxell said. Besides, it is angled to focus on a seating area near the display cases and provides no view of the artifacts. Meanwhile, deputies have found no witnesses.

"You look at where those coins are, and it looks like it could be a crime of opportunity where someone may have taken advantage," Troxell said.

Investigators have not ruled out the possibility that someone might be out to snatch the county's history.

In May, a 1755 engraving of John Campbell, the fourth earl of Loudoun and the man for whom the county is named, was stolen from Leesburg's Thomas Balch Library. The picture, which an appraiser told library officials was worth $5,000, had hung undisturbed for years.

Loudoun has had a working courthouse on the same patch of land in Leesburg since shortly after the county split from Fairfax County in 1757. In that time, the grounds also have been the site of commercial activities and a schoolhouse. The complex changed hands more than 100 times during the Civil War, meaning soldiers from both armies camped there.

"When you look at these artifacts, you see the whole history of the county before you," said Horne, who sits on a county task force for preservation of the grounds.

Horne said that the coins belong to the people of the county and that their theft is a shame.

"They were safe in the ground until you dig them up, and then you dig them up and someone takes them," he said. "They're irreplaceable."

How much they are worth is another question. Although sheriff's officials said the missing coin was a King George III penny, a study done as part of the 1997 archaeological survey identified the coin as a worn half-penny. The archaeologists wrote that the coin featured most of the word "George," along with the king's profile.

Richard Doty, numismatic curator for the Smithsonian Institution, said that neither coin is particularly rare and that the coin in question is in such poor condition that it probably wouldn't fetch much money. He said a thief who tried to sell it probably would be given "the bum's rush, which would kind of serve him right."

American Numismatic Society curator Robert Hoge, who agreed with Doty that the coin probably was of little monetary value, called the theft "tragic" nonetheless.

"Price isn't everything," he said. "People don't realize, when something is gone, it's gone. It represents information that can never be recovered."