Boston's police commissioner told lawmakers conducting the first congressional hearing on the Marathon bombings that government should tighten security around celebratory public events and consider using more undercover officers, special police units and technology, including surveillance cameras — but only in ways that don't run afoul of civil liberties. 

"I do not endorse actions that move Boston and our nation into a police state mentality, with surveillance cameras attached to every light pole in the city," Commissioner Edward Davis said in prepared remarks for the House Homeland Security Committee. "We do not and cannot live in a protective enclosure because of the actions of extremists who seek to disrupt our way of life."