Waltham mourns death of veteran police officer Paul Tracey, struck and killed in crash

A memorial of red and white flowers and blue ribbon with the wording 'Hero' grew on top of a cruiser outside the Waltham Police Department on Thursday, while community members stopped by with lunch and other donations.

Less than 24 hours before the outpouring of community support, Paul Tracey, a 28-year veteran of the department, drove the cruiser for the final time, to a detail site on Totten Pond Road.