The Tsarnaevs trained at the mixed martial arts gym under reporter Andrea Crossan’s home. And, it turns out, that some of the best fighters in MMA come from the Caucasus region that also produced the Tsarnaevs.The Tsarnaevs trained at the mixed martial arts gym under reporter Andrea Crossan’s home. And, it turns out, that some of the best fighters in MMA come from the Caucasus region that also produced the Tsarnaevs.