Jeff Bauman, who lost his legs in the Boston Marathon bombing and whose injuries were captured in an iconic photo of the attack, testified today that he locked eyes with with Tamerlan Tsarnaev moments before the explosion.

Bauman said he was near the finish line with a friend when a suspicious-looking man nudged him.

"He didn’t look like anyone there. He was alone, wasn’t watching the race," Bauman testified. "He didn’t look like he was having fun like everyone else. I looked at him, he kind of looked at me, stared down at me."

Bauman, who was widely seen in a news photo being wheeled away from the scene alongside a man in a cowboy hat (Carlos Arredondo),​ walked into court this morning wearing shorts, exposing his prosthetic legs. 

Dzhokhar Tsarnaev, the brother of Tamerlan Tsarnaev, is on trial in Boston for the attack and could get the death penalty if convicted of charges he helped carry out the 2013 bombings. 

The accused turned to watch Bauman walk into the witness box.

Throughout his testimony, Bauman appeared to frequently glance toward TsarnaevBauman was upbeat and seemed full of positive energy as he recounted the events of that day.

Bauman, along with friends, went to the race, his first ever, to watch his then girlfriend (now wife) run. After watching her at Mile 17, mid-race, they decided to go near the finish line to watch her cross.

In the thick of the boisterous and happy crowd, a passerby nudged him and turned and looked back, Bauman testified. That's when he locked eyes with Tamerlan Tsarnaev. 

Tamerlan Tsarnaev, 26, died following a gun battle with police days after the bombing. 

Saw bag unattended

Bauman said he then focused on the race, looking for his girlfriend.

"I looked back and I saw a bag there, unattended. I thought that was weird. I looked around for him."

"It looked like a regular school backpack, a regular backpack," he said. "I just thought it was weird. Like when you’re at the airport, that kind of went through my head, when you see any unattended luggage you notify authorities. I just thought it was weird."

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Dzokhar Tsarnaev could get the death penalty if convicted of charges he helped carry out the 2013 bombings. (Jane Flavell Collins/Reuters)

He turned and said to his friends that maybe they should move past the finish line, to look for his girlfriend. One of the friends said they should wait five more minutes.

"Two seconds later I saw a flash, heard three pops, and I was on the ground," Bauman said.

"I lifted my head and saw the chaos around me, the smoke, all the stuff going on. People were screaming, my ears were ringing."

He saw his friend’s leg was really bad, saw bone. Then, "I looked down and saw my legs. It was just pure carnage. I could see my bones sticking out."

'This is messed up'

"I was thinking, ‘This is messed up, this is messed up, this is  messed up.’ That’s all I was thinking."

Bauman said he thought he was going to die and made peace with himself, but then heard a second explosion. 

He said something 'clicked' and he renewed his emotional focus.

"I was just, kind of, just 'I'm not going to lay here. I’m going to try something."

He said he sat up as people rushed toward him, grabbing shoelaces, belts, anything to make tourniquets.

"I see a guy in a cowboy hat. He’s yelling at me 'OK, stick with it.' I was focusing on him. He was keeping me calm. I had hope at that point."

Bauman said he was lifted into a wheelchair and rushed to the medical tent and then into an ambulance.  

He had three surgeries, Bauman said, and when he woke up he wrote down on a notepad what he remembered.

"I recalled this suspicious kid that I saw. I didn’t know for certain that he was what happened, but I knew it was, at that  point, it was pretty clear in my head what happened."

"I had only one goal at that point which was to tell whoever I could what I knew. I wrote down what happened, I saw the kid, I know what happened."

He was in hospital for a month and a day, and in rehab until two months ago. He still has constant ringing in his ears.

"I can't hear that well at all," he said.

Before testimony began Thursday, Tsarnaev's lawyers complained to the judge that the survivors' testimony from the previous day was too gruesome and should be limited. Defence attorney David Bruck said under the federal death penalty law, victim-impact testimony is supposed to be presented during the second phase of the trial.

However, U.S. District Judge George O'Toole Jr. rejected the request. 

With files from The Associated Press