DALLAS Dr. Kenneth Salyer was a 27-year-old resident at Parkland Hospital on call for head injuries when he got word a new patient was being rushed to the ER.

"A nurse ran into the room and said, 'The president's been shot,'" Salyer says.

Dr. Kenneth Salyer was a 27-year-old resident at Parkland Hospital on call for head injuries on Nov. 22, 1963.

But nothing prepared him for what he saw.

"He was still breathing," he says. "It's sort of agonal, labored, close-to-your-last sort of breaths. But he still was breathing."

As he looked down at the president's grave wound, Salyer says he thought it was a "major high-velocity injury."

"And it's in a critical place," he said. "So the chances are pretty slim. And if he did survive, what would we have?"

President John Kennedy, who suffered from chronic back pain, wore a heavy, corset-like brace that went from his chest to below his waist.

When the president's clothes were removed, Salyer was surprised by what he found. Kennedy, who suffered from chronic back pain, was wearing a heavy, corset-like brace that went from his chest to below his waist. He believes it cost Kennedy his life.

He's looked at the autopsy report and studied, frame by frame, the 26-second Zapruder film, which captured the assassination and the wounding of Texas Gov. John Connally.

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"The first shot that hit him went through the soft tissue of the back of his shoulder ... and exited through his trachea," Salyer says. "That same bullet went through John Connally's chest, through his right hand and into his thigh and knocked him completely down in the car."

The next shot -- the fatal shot -- hit the president in the head.

"And then this is the second shot of JFK. ... He's still upright as a target, because he has the brace on, which makes it possible for Lee Harvey Oswald to hit him with a second shot," Salyer says. "I think that would not have happened if he had gone down like John Connally did."

Kennedy's injuries were massive. Just 30 minutes after the shooting, he was pronounced dead.

"I'd lost my hero in my hands, and he was gone," Salyer says.

It was then that Salyer saw Mrs. Kennedy approach her husband's body -- a scene he will never forget.

"We had covered him up after pronouncing him," he says. "She came over and leaned over his chest and took his hand out and put a ring on and did a ring ceremony as I witnessed that very delicate moment."

A delicate moment on one of America's most tragic days.