TOWN OF HEMPSTEAD (CSBNewYork) — A Christmas time caper still has investigators stumped on Long Island.

As CBS2’s Jennifer McLogan reported, expensive jewels were stolen from a Costco location in Oceanside, and investigators are looking into whether the thief or thieves were hiding inside when the warehouse closed for the holiday.

A glass case filled with nearly $100,000 in jewels was pried open during the Christmas Eve caper, which remains unsolved.

“There could have been two people – one could have been the lookout,” Nassau County Police Det. Lt. Richard LeBrun told McLogan.

He said when the alarm sounded just before 11 p.m. at the Costco on Hampton Road, police discovered the display case cracked open and the crook – or crooks – gone.

“They come with more than one person. So one goes over there, one goes over there,” said one shopper.

“I would think that they would have security cameras to detect motion and alert management,” another added.

It happened on Christmas Eve and Costco was not open on Christmas Day.

“Could be an inside job or something,” one man said.

“They know how to do it, because they in and they hide,” added another.

Police say that’s one theory.

“Stayed in the store and waited for them to close,” LeBrun said, confirming it’s possible the thief or thieves found a spot where they couldn’t be detected by motion sensors or alarms.

Surveillance video shows two separate men spotted at different times near the jewels – one with a beard about 5 feet 11 inches to six feet tall, another also wearing all black – apparently casing the joint.

Police say $92,000 in jewels is now missing.

“Nobody’s in there. They’re opening and taking almost that amount,” one shopper said.

“Well it might be an inside job,” another added.

“Surprising they don’t have been security that would prevent that,” said another.

If the burglars did hide, where? Cameras are located throughout the warehouse.

Detectives say the surveillance video shows two possible suspects leaving the Costco at separate times – both on foot, heading in an unknown location. One was carrying a blue bag loaded with diamond jewelry.

Costco would not comment, because the investigation is ongoing.

Watch & Listen LIVE