The FBI did not initially share with Boston police the warnings it had received from Russia about one suspect in last month's marathon bombings, despite the work of four city police representatives on a federal terrorism task force, Boston's police commissioner told Congress on [May 9]. Boston police learned about the Russian security service warnings only later. The congressional hearing was the first in a series to review the government's initial response to the attacks, ask what information authorities received about Tsarnaev and his brother before the bombings and consider whether everything was handled correctly. Some lawmakers questioned whether Boston police could have more thoroughly investigated Tsarnaev after 2011, based on Russia's vague warnings then to the FBI and CIA or the discovery by the Homeland Security Department in 2012 that he was traveling to Russia for six months, and whether Justice Department rules intended to protect civil liberties constrained the FBI's own inquiry. Led by the FBI, Joint Terrorism Task Forces operate in many cities as a way to bring federal, state and local officials together to share information. The model has existed for decades but, after 9/11, task forces sprouted up in cities nationwide to ensure that police were not out of the loop on investigations like the one the FBI conducted into Tsarnaev.