Workers returning from lunch Monday at Data Metalcraft in Chaska noticed almost immediately that something was wrong. Things were in disarray, and some large copper sheets appeared to be missing.

Turned out, it was an inside job -- sort of.

On Wednesday, Minneapolis police arrested a former Data Metalcraft employee after he tried to sell two copper sheets to a scrap metal dealer.

Chaska police searching the suspect's home found 15 more of the sheets belonging to the sheet metal fabricator.

In all, police said that 22 copper sheets measuring 8 by 3 feet -- about as big as plywood panels -- were taken from the company, a loss estimated at $13,500.

Data Metalcraft president Gene O'Brien said he thinks the suspect also may be responsible for at least another $10,000 in thefts that were detected during a recent inventory.

"I certainly hope the prosecuting attorney throws the book at him," O'Brien said.

The suspect, 40, had not been charged Thursday and was being held in Hennepin County jail on suspicion of burglary, theft and receiving/concealing stolen property.

Scrap metal is in high demand, forcing increased prices and prompting thefts of all things metal: wire, aluminum siding, catalytic converters, even beer kegs. "At times, we feel like vultures are circling around the building," O'Brien said.

After O'Brien alerted police Monday, authorities sent out a crime alert via an electronic network and the company sent a bulletin to all scrap dealers within 300 miles.

When the suspect showed up Wednesday at a scrap business in Minneapolis, the dealer became suspicious and called Chaska police, Chief Scott Knight said. Knight contacted Minneapolis police, who confirmed that the suspect had some of the stolen copper and arrested him.

Scrap dealers are "really on guard," Knight said. "Copper is a very prime theft target, and they are tuned in to what's going on."

O'Brien said the suspect worked for Data Metalcraft for four months, as recently as May. He was let go after he "ran afoul of our attendance policy" and failed to show up for work, O'Brien said.

Knight described Data Metalcraft as a secure facility, but O'Brien said "it's not as secure as it's going to be." A new system with locks and buzzers soon will be installed, he said.

Kevin Duchschere • 612-673-4455 • kduchschere@startribune.com