BOSTON (CBSNewYork) — A Boston Transit Police Officer injured in a shootout with the Boston Marathon bombing suspects remained in critical, but stable, condition Sunday.

Massachusetts Bay Transportation Authority Police Officer Richard Donohue Jr. was shot in the thigh, hitting his femoral artery, in a violent exchange between Tamerlan and Dzhokhar Tsarnaev Thursday night, CBS Boston reported.

In a news conference at Boston’s Mt. Auburn Hospital Sunday, hospital officials said Donohue remained in the surgical intensive care unit but doctors are “cautiously optimistic.” He is expected to walk again, doctors said.

Dr. David Miller said Sunday morning Donohue was able to wiggle his toes and squeeze his wife’s hand for the first time, CBS Boston reported.

Miller said Donohue suffered severe blood loss from the gunshot wound to the point his heart almost stopped, CBS Boston reported.

“The care he received at the scene and in the emergency room was well-organized, rapid and outstanding,” Miller said.

Donohue remained of a mechanical ventilator and heavily sedated as of Sunday, doctors said.

“I’m hopeful he’ll be able to get off the ventilator,” Miller said in the CBS Boston report. “It’s standard care for someone who had sustained a massive blood transfusion.”

Donohue’s brother, Ed Donohue, is a Winchester police officer. He credited his brother and other officers for their heroic actions, CBS Boston reported.

“As a brother, a fellow officer and an American, I can’t describe the pride I have for Dick and other emergency personnel and how they acted Thursday night,” he said.

In the Thursday night incident, the suspects allegedly shot and killed MIT Police Officer Sam Collier, and then carjacked a man in a Mercedes-Benz, police said.

From there, the two suspects carjacked a man in a Mercedes-Benz, keeping him with them in the car for half an hour before releasing him at a gas station in Cambridge, police said. The man was not injured.

Police say the Boston Marathon bombing suspects used their carjacking victim’s ATM card before a gunfight with authorities.

Authorities said both suspects were in the Mercedes when they encountered police, and then hurled explosives and exchanged gunfire with officers.

CBS News Senior Correspondent John Miller reported that the explosives thrown at officers was the same type of pressure cooker bombs that were used in Monday’s marathon attack.

That was when police said a Donohue was seriously injured. Tamerlan Tsarnaev was also critically injured during the exchange with police and later died at a hospital, authorities said.

His brother, Dzhokhar, then got back into the car to escape, backing over his brother’s body in the process, CBS News reported. Dzhokhar Tsarnaev was captured Friday night.

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