MADISON, Wis. -

A device used to spot people who are missing or fleeing in large areas has disappeared, a spokeswoman said.

Dane County Sheriff's press information officer Elise Schaffer said Thursday that a Middleton parks department employee found the heat-vision device near University Avenue and Parmenter Street.

The sheriff's office had asked for the public's help Tuesday in finding the thermal imaging monocular, which it said had disappeared on one of numerous calls for service the night of Nov. 19.

The monocular is used by law enforcement to search for lost children, dementia patients or anyone who may be missing or fleeing police, according to the news release. The device is especially valuable during winter months when missing people could be exposed to harsh elements, Schaffer said.

Schaffer said the monocular is worth about $9,000.