Boston police bought a surveillance tool with a chunk of money hidden from the public

For the full investigation, click here.

A new investigation by WBUR and ProPublica looks into the Boston Police Department's purchase of a powerful surveillance device with money seized from alleged suspects.

Host Scott Tong speaks with WBUR investigative editor Christine Willmsen about concerns about the surveillance device and the way it was paid for.

This story was supported by the Pulitzer Center.