© Adapted by WhoWhatWhy from Dave Newman / Flickr (CC BY 2.0)Tamerlan Tsarnaev
This designation existed right up to the time the bombs went off at Boylston St. on April 15, 2013.
Tamerlan Tsarnaev's heavily redacted immigration records, known as an A-file (alien file), were released in February under the Freedom of Information Act and posted online by US Citizenship and Immigration Services (USCIS). FOIA has a "frequently requested record" provision where multiple request for the same record triggers a "reading room" (posted online) treatment of the records. WhoWhatWhy was one of those requesters.
For context, it's important to note that soon after the bombing, uncomfortable questions were raised by WhoWhatWhy when it became clear the FBI had long been aware of Tsarnaev. Even some of the mainstream outlets, which almost uniformly have accepted the government's version of events, couldn't ignore this reality.
The Bureau steadfastly maintains that it determined the elder Tsarnaev (who died in an altercation with police three days after the bombing) was not any kind of a national security threat. It also denies ever having asked him to be an informant.
Continue reading on WhoWhatWhy.
Comment: As Henry points out further on in the article, the FBI initially denied having any awareness of the Tsarnaev's, a line they modified after their mother said the FBI "used to come [to our] home ... they were controlling his every step." Even though they claimed they had cleared him of any link to terrorism, they had him on a watchlist as "may be armed and dangerous". They also claimed Tamerlan first came to their attention after a Russian warning, alleging he was an adherent "of radical Islam and that [he] was preparing to travel to Russia to join unspecified 'bandit underground groups' in Dagestan and Chechnya." But he was on the watchlist months before that.