The younger brother, Dzhokhar, hopped in the back seat. Tamerlan took over the driving.
"They asked me where I'm from. I told them I'm Chinese," the carjacking victim told CNN-affiliate WMUR. "I asked them if they were going to hurt me. They said they won't hurt me. I was thinking, 'I think they will kill me later.'"
The man with the gun demanded cash. The carjacking victim handed over $45. They wanted more money so he gave the his ATM card and the passcode. Dzhokhar was seen on surveillance video at a Bank of America ATM at 11:18 p.m.
Both brothers were said to love high-end cars, and now they were in a carjacked Mercedes darting from Allston to Watertown to Cambridge. Eventually, the fuel tank neared empty.
The brothers mentioned something about New York as they drove, according to the driver. Authorities have since said the two planned to attack Times Square.
The Mercedes pulled into a Shell gas station on Memorial Drive. At that time of night, the station only accepted cash to pump gas. Dzhokhar went inside to pay. According to the Boston Globe, Tamerlan put his gun in the door pocket to fiddle with a navigation system.
The carjacking victim saw this as his opportunity to flee. "I jumped out of the car and ran away across the street," he told WMUR.
Tamerlan tried to grab him, "but I ran very fast." He could hear the man swearing as he sprinted for his life.
"It was very scary at that moment," he recalled. "For me, I'm so lucky."
He burst through the door of a nearby Mobil gas station so hard, the clerk was angry -- until he saw the panic on the man's face and heard his pleas to call police. The carjacking victim curled up in a back room and hid.
The men in the stolen SUV sped off.
Somewhere along the way, the two stopped to pick up their other car: a green Honda Civic with a Massachusetts tag 116GC7. Earlier in the day, authorities had put out an all-points bulletin for that exact vehicle.
A dramatic shootout in Watertown
"Heading to Watertown," the voice said over police dispatch.
Two hours had passed since the shooting at MIT. The next hour was followed by a bizarre carjacking.
Authorities wondered: Were the two linked?
The carjacking victim had left his cell phone in the SUV, and police were using it to monitor the vehicle's every movement. It was now shortly after 12:30 a.m. Friday.
Many Watertown police officers had ended their shift at midnight and were headed home when they heard a possible suspect in the MIT shooting was in their vicinity.
"All they knew at the time was this was related to the MIT murder over there," Watertown Police Chief Edward Deveau told CNN.
Officer Joe Reynolds was the first to spot the stolen vehicle, driving in tandem with a Honda Civic. He notified the station that he had the suspects in sight.
"OK, do not try to pull their vehicle over until we get you some more backup," he was told.
Officer Reynolds continued to follow them. At least seven officers soon arrived.
On Laurel Street, a side road in the middle of a neighborhood, the two brothers stopped their vehicles and immediately started shooting. "They took the gunfight to us," Deveau recalled.
Officer Reynolds kicked his cruiser in reverse to try to distance himself from the suspects.
Andrew Kitzenberg lives in a three-story home at 62 Laurel, the location where the gun battle began. He saw two men crouched behind the SUV, opening fire on police.