Security cameras at a Boston gym show the two brothers accused of carrying out the Boston Marathon bombings working out together three days before the attack.
Surveillance video recorded at the Wai Kru mixed martial arts center and obtained by CNN
shows Tamerlan Tsarnaev, 26, and Dzhokhar Tsarnaev, 19, arriving with a friend shortly before 2:45 p.m. on April 12.
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The gym's manager, who wanted to be identified only as Michael, told the cable news network he noticed that Tamerlan had shaved the full, bushy religious beard he had been sporting for about two years but did not ask about it. He said the older brother was extremely opinionated and outspoken about his Muslim religion.
"Shaving the beard may be a way to blend in, not to attract scrutiny from security services in carrying out the Boston attacks," CNN terror analyst Paul Cruickshank said in a televised interview as he reacted to the footage.
According to Michael, Tamerlan, a nationally ranked Golden Gloves boxer, trained at Wai Kru several times a month for free as a professional courtesy. Dzhokhar, however, had come just "two or three" times in the past couple of years.
In the video, Michael, who stayed off-camera, asked the Tsarnaevs to take off their street shoes, one of the gym's posted rules. While Dzhokhar immediately complied, Tamerlan refused and argued with the manager, who later sent the owner an e-mail asking him to ban the older brother.
Once in the ring, Tamerlan continuously worked out with a jump rope and stretched. Cruickshank suggested he was preparing to carry out the bombings.
"We've seen with Western militants, wanna-be jihadists, a real emphasis on physical training, physical fitness, wanting to be prepared for jihad," Cruickshank said, as he responded to the tape.
According to CNN, FBI agents have seen the security footage from Wai Kru but took only a few screen grabs to use as still photos. The friend who accompanied the two brothers to the gym that day was reportedly later questioned and released by the FBI.
Michael said he told investigators about another Chechen named Ibragim Todashev, a friend of Tamerlan's who also worked out at Wai Kru.
Todashev was shot and killed by an FBI agent last week while being questioned about a triple homicide in 2011. Law enforcement officials are investigating whether the Tsarnaev brothers were involved in that incident.
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