Russia Finally Reveals Why Tamerlan Worried Them New information could have prompted further FBI investigation: AP By Matt Cantor, Newser User Posted Apr 28, 2013 8:17 AM CDT 120 comments Comments This Monday, April 15, 2013 photo shows bombing suspects Tamerlan Tsarnaev, 26, center right in black hat, and his brother, Dzhokhar A. Tsarnaev, 19, center left in white hat. (AP Photo/Bob Leonard) (Newser) – Russian officials have finally revealed what fueled mounting concerns about Tamerlan Tsarnaev: After they wiretapped his phone, they caught him talking about jihad with his mother in 2011. In another recorded conversation, mother Zubeidat Tsarnaeva spoke to a person in southern Russia who is the subject of a separate FBI inquiry, the AP reports. But Russian officials didn't tell the FBI about the conversations until after the Boston Marathon bombings. Had federal investigators known about the evidence, they might have had grounds for a further probe, the AP notes. "Would we have gone farther?” a US official asks, per the New York Times. “Maybe, maybe not.” Though jihad was mentioned, the calls didn't refer to any set plot, the Times notes. Meanwhile, details of Dzhokhar Tsarnaev's imprisonment are emerging: He's in a cell with a solid steel door containing an observation window and a food and medication slot, an official says.