Boston Police Department Integrity Policy
http://www.cityofboston.gov/Images_Documents/rule113_tcm3-9572.pdf
note:
"take all necessary and prudent actions to expose those who knowingly violate the public trust."
"Employees shall conduct their private affairs so as not to reflect unfavorably on the Boston Police Department; or in such a manner as to affect their ability to perform their duties honestly, effectively, fairly, and without impairment."
"Police officers shall exhibit the utmost respect for the legal rights of all."