The University of Wisconsin Police Department recovered 600 bikes — most of them probably stolen — after dismantling a “chop-shop” bike operation last week.

In a news conference Tuesday, UWPD Chief Susan Riseling said the department would charge two men that allegedly stole the bikes once UWPD finds out how many of the bikes were actually stolen.

UWPD executed a search warrant Thursday in four Madison-area locations, discovering more than 1,000 bikes, with 600 of them having a serial number and identified as likely stolen.

UWPD suspects they are now in possession of bikes stolen up to 10 years ago, Riseling said. For bikes stolen between five and 10 years ago, police databases have been purged and UWPD is requesting victims report their bike theft again.

Victims of bike theft will be reunited with their bike no more than 10 days after re-notifying UWPD, Riseling said.

“Because the databases are what they are and they’ve been converted, and we’re also dealing with every jurisdiction in Dane County, every single jurisdiction, we at the university police do not have those police reports,” Riseling said.

The investigation began in May 2014 after UWPD received information from an individual in a letter outlining the operation, Riseling said, information that UWPD was later able to confirm as true.

Charges are pending against Duane J. Tessmer, 53, Town of Madison, and Michael J. Bingen, 57, Village of Muscoda, Riseling said. Once people reclaim the stolen bikes, it will help determine the charges, which could range from misdemeanor to felony charges, she said.

The stolen bike operation was essentially a “chop-shop” for bikes, Riseling said, as people who purchase $1,000 to $2,000 bikes do not usually dismantle them, she said.

“We estimate that more than 16,000 bikes have been stolen in Dane County in the last 10 years,” Riseling said. “Less than half are actually reported to the police. Of those reported stolen, only about 4,200 have serial numbers.”

UWPD executed the search warrants in a bike shop in Muscoda, an apartment in the Town of Madison, a storage unit in the City of Madison and a farm in the Town of Windsor.

UWPD encouraged people whose bikes have been stolen and who have the bikes’ serial numbers to complete a form online at http://uwpd.wisc.edu/biketheft.