The mayhem that night started with the fatal shooting of MIT campus officer Sean Collier, after which the two suspects -- Dzokhar and his 26-year-old brother Tamerlan -- hijacked another vehicle, allegedly bragging to the carjacking victim about their involvement in the Boston Marathon bombing. They let the black SUV's owner go, uninjured, after forcing him to withdraw money from an ATM.
However, his cell phone remained in the car, which gave police their first lead in tracking the suspected bombers. Authorities tracked the cell signal to a quiet residential street in Watertown, where a firefight ensued.
Armed with handguns, rifles and at least six bombs -- some of which were hurled at officers from the stolen vehicle -- the suspects launched their attack against responding police officers.
“The two brothers are shooting at my first police officer that’s responded and now, within seconds, I have two or three other police officers that pull up,” Deveau (Watertown Police Chief) told Blizter. "We estimate that there [were] over 200 shots fired over a five to 10 minute period."
Despite their surplus of weapons and ammunition, Deveau said the older Tsarnaev ran out of rounds while approaching officers on foot. It was then that one officer made his move, tackling the suspect to the ground before handcuffing him. The younger brother managed to escape custody, but not before running over his brother.
"One of [the officers] yells out 'look out' and here comes the black SUV, the carjacked car, directly at them," Deveau recalls. "They dive out of the way, yet he runs [over] his brother and drags him that short distance down the street."
"In effect, killing his brother?" Blitzer asked. "Yes, that's what we think," Deveau replies.