Never-before-seen video obtained by CNN shows Boston bombing suspects Tamerlan and Dzokhar Tsarnaev only three days before allegedly carrying out the attack.
The footage, recorded on security cameras at Boston's Wai-Kru Mixed Martial Arts gym, shows the brothers entering the building and doing various exercises in the facility's boxing ring. The manager of the gym told CNN that he was surprised by Tamerlan's appearance that day: the 26-year-old, who had become an increasingly more devout muslim toward the end of his life, arrived at the gym without the "bushy, religious beard" that he had worn for two years.
The manager also told CNN that Tamerlan caused a scene that day after he and his brother were asked to remove their shoes at the door, per gym policy. While Dzkokhar removed his shoes without issue, Tamerlan is shown in the video arguing with the manager, who said he later asked the gym's owner to ban the "arrogant" and "selfish" Tsarnaev.
Tamerlan, who was an accomplished prize fighter, worked out frequently at Wai Kru. Authorities have linked the him and his brother to the grisly 2011 murders of three people -- including Brendan Mess, another Wai Kru regular -- who were found with slashed throats, covered in marijuana.
Three days after the video, the brothers allegedly planted homemade explosives at the finish line of the Boston Marathon, killing three and injuring 264. Tamerlan was killed during a shootout with police on April 19. A badly injured Dzokhar was apprehended by police later that day. The 19-year-old has since recovered enough to resume walking and talking, according to reports.