ABC News

A Chicago jewelry heist  resembled a scene from "The Score," in which Robert DeNiro plays a jewelry thief who relies on an "inside" source (Edward Norton) to pull off a sophisticated robbery that out-maneuvers a state-of-the art security system.

This week, thieves broke into a Chicago sushi restaurant, knocked through a the wall to gain entry to Steve Quick Jeweler next door, sawed a hole in a steel, cement-fortified safe, and made off with half a million dollars worth of expensive gems.

"It wasn't amateurs," owner Quick told ABC's WLS-TV. "This was a sophisticated operation."

Quick suspects an inside job because the thief seemed to know exactly how to avoid motion detectors rigged to send alarms directly to police. The burglar also knocked through the wall from the adjoining restaurant in just the right place.

The jewelry store owner tells WLS that the thief crawled under his desk to reach the two-ton safe, known as a "TL-30? because it's supposed to take a seasoned burglar at least 30 minutes to crack. The thief then sawed a four-inch hole near the bottom of the safe, removing gems that his family had collected over 25 years.

Quick calls the loss "devastating," though he believes most of it will be covered by insurance, and says he is grateful that no jewelry belonging to customers was taken. In 1999, an armed robbery at the same shop netted $750,000 and injured a store employee.

Quick has already improved his security system to cover "the blind spots" that the thief seemed to know so well.  Chicago police tell ABC News that the Quick jewelry caper is being investigated.