On April 19, 2013, the city of Boston was under lock down.
Overnight, there had been a shooting, a carjacking, a chase, a gun battle with police. The Tsarnaev brothers had been identified as suspects in the marathon bombings.
Tamerlan was dead and police were looking for his brother, Dzhokhar. Massachusetts Governor Deval Patrick asked Boston residents to shelter in place.
"In other words," he said. "Stay indoors with [your] doors locked and [don't] open the door for anyone other than a properly identified law enforcement officer. And that applies here in Watertown where we are right now, also Cambridge, Waltham, Newton, Belmont and at this point all of Boston, all of Boston."
And so I sheltered in place. During the course of that day, images of the Tsarnaevs were everywhere on TV. Many of the photos were of Tamerlan sparring at a mixed martial arts gym called Wai Kru. I knew the Wai Kru gym.
I live above it.
It made me wonder how many times I may have walked my dog past Tamerlan going in to train. Before that day, I'd never had an interest in that gym below my apartment. But now, I wanted to know what drew Tsarnaev to Wai Kru and to mixed martial arts.
What I discovered was, for young men like Tamerlan, MMA fighting was an obvious outlet.
The sport is huge in the Caucasus region. And for those who are good at it, it can be a ticket to the American dream.
That's how I discovered Khabib Nurmagomedov.
Nurmagomedov is a mixed martial arts fighter. Like the Tsarnaev's, Nurmagomedov has roots in the North Caucasus. He's Muslim and from the same native ethnic group, called Avar.
But that's where the similarities end. Nurmagomedov is a success story. He trains at the American Kickboxing Academy in San Jose, California. Javier Mendez is his coach.
"He's very dedicated, a very hard worker, extremely focussed and extremely talented," Mendez said.
Nurmagomedov is in the lightweight division for the Ultimate Fighting Championship.
He currently has one of the longest undefeated streaks, with 22 consecutive victories. Nurmagomedov, called "The Eagle," is known well in the US and in his home of Dagestan.
He said he chose the Eagle nickname because it's the symbol of his home. It's also why he wears a huge lambskin hat before his bouts.
“The Papakha is the symbol of my people," said Nurmagomedov. "All the elder people wear it — not just my people but all the people of the Caucasus. I know that the UFC is more than just a sport, it's a business. You need to have a show. For Americans, the hat is exotic. Many think it's a wig. No, it’s not a wig. I tell them it's the symbol of my people.”
There are about 9 million people in the North Caucasus. And they breed fighters.
Nurmagomedov has been fighting since he was a child. There's a video set to music of an eight-year-old Nurmagomedov wrestling with a bear cub.
The adults stand around and watch as the 8-year-old grapples with a bear larger than he is. Nurmagomedov laughs off the bear wrestling. But he's dead serious about his career.
Mixed martial arts combines Thai boxing, Brazilian Jiu-Jitsu and the Russian martial art called Sambo. Like most MMA fighters from Russia and the Caucasus, Nurmagomedov's strongest discipline is Sambo. Sambo was created by the Soviet Army to improve soldiers' hand-to-hand combat abilities.
Nurmagomedov says eventually he wants to open an MMA gym back in Dagestan. Fight fans might not know that 'The Eagle' is from Dagestan or where Dagestan is. He's just that fighter who wears that crazy white wig.
“They say 'are you from Pakistan, or Kazakhstan?' I'm always explaining that Dagestan is a republic of Russia and that it’s in the south of Russia near the Caspian Sea," he said.
For young men like Nurmagomedov, the mixed martial arts gym is a home away from home. It's a community where they fit in. They can meet people who speak their language and understand their culture.
I don't know why Tamerlan Tsarnaev liked going to the Wai Kru gym. I don't know if he imagined having the success that Nurmagomedov has achieved. And I still don't know that much about mixed martial arts.
But I follow The Eagle.
On April 19, 2014, he fought a Brazilian fighter, Rafael dos Anjos. Nurmagomedov won. It was a unanimous decision.