BOSTON (AP) — A carjack victim on Thursday described his harrowing ride at gunpoint with the Boston Marathon bombers three days after the attacks and the moment he made the terrifying decision to bolt from the car.

Dun Meng, a Chinese national who moved to the U.S. in 2009 to attend Boston’s Northeastern University, testified in bomber Dzhokhar Tsarnaev’s trial that he had left work in Cambridge late on the night of April 18, 2013, when he pulled over and returned a text message.

A car quickly pulled up behind him, a man got out and knocked on his passenger-side window. Meng said he thought the man was asking for directions, so he lowered his window. The man then reached in, opened the door and quickly jumped into his car, Meng said.

“He point a gun to me — right to my head — he ask money first, ‘Where’s your cash?'” Meng said.

Meng said he later learned the man was Tamerlan Tsarnaev, one of two brothers who had detonated twin bombs near the finish line of the marathon, killing three people and injuring more than 260. Hours before the carjacking, the FBI had publicly released photos of the Tsarnaevs as suspects in the bombing.

Meng said he told Tamerlan Tsarnaev he only had about $40 in cash, and Tsarnaev pulled the magazine out of his gun to show him the bullets inside.

“He told me, ‘You know I’m serious so don’t be stupid.'”

Meng said Tsarnaev asked him if he knew who committed the Boston Marathon bombing.

“He said, ‘I did it, and I just killed a policeman in Cambridge,'” Meng said.

Meng said he realized then that this was more than a robbery. “I was very scared,” he said.

Prosecutors said shortly before the carjacking, the Tsarnaev brothers shot Massachusetts Institute of Technology police officer Sean Collier in a failed attempt to steal his gun.

After driving around for 20 or 30 minutes, Meng said, Tamerlan told him to pull over on a street in Watertown and a sedan pulled up behind them. Meng said Tamerlan helped a man in that car load items from the sedan into Meng’s Mercedes-Benz SUV.

Meng identified the second man as Dzhokhar Tsarnaev, pointing to him in court. “The gentleman over there,” he said.

Meng said Tamerlan drove his car to a bank machine in Watertown, where Dzhokhar asked him for his pin number and then withdrew money from his account.

Tamerlan asked Meng: “Can your car go out of state, like New York?” he testified.

Meng said he decided to make his escape after Tamerlan pulled into a gas station and Dzhokhar went inside to pay.

“Every time when I recall this, I think this is the most terrifying moment. It’s the most difficult decision in my life,” Meng said.

He unbuckled his seatbelt, opened the car door and dashed into the street.

“I can feel he was trying to grab me,” he said. “He was shouting. He was saying some word.”

Meng said he ran across the street to another gas station.

The jury saw dramatic surveillance video of Meng running inside the station, holding the door shut and begging the clerk to call 911. He then crouches down, goes behind the counter and crawls into a storage room.

“I am really worried they would follow me, so I was trying to find a place to hide,” he said.