Did Russia withhold details about Tsarnaev? May 11, 2013 -- Updated 0124 GMT (0924 HKT) (CNN) -- Russia withheld details from U.S. officials about suspicions of Boston Marathon bombings suspect Tamerlan Tsarnaev in 2011, information that could have altered the course law enforcement followed, according to a published report. The Wall Street Journal reported Friday that while Russia did alert U.S. authorities about Tsarnaev's possible extremism, it kept out some facts, namely text messages referencing his desire to join a militant group. The newspaper cited U.S. officials who have been briefed on the matter. However, the sources added that the U.S. also likely would have withheld such details for fear of divulging intelligence sources and methods.