Welcome to JFK and The Enduring Secret.

I'm your host, Jeff Crudell.

There was the terrible ride to Parkland Hospital.

And for those in the presidential motorcade, the what-ifs, the guilt, were just beginning.

We ran side by side, Jackie, holding on to the stretcher on one side.

I'm running on the other.

The president's friend, Dave Powers, now director of the Kennedy Library in Boston,

remembers talking to a grief-stricken Bill Greer, the Secret Service agent who drove Kennedy's car.

What if, what if they'd sped out of Dealey Plaza after the first shots but before

the fatal one? I thought that always, and so did he, you know, Bill, all those agents were very

close to us and that they felt so bad. If the driver of the president's car

had stepped on the gas after the first two shots...

Yes.

What...

That president would be alive today,

and he'd be 71 years old,

and he'd be the director here,

and I'd be the assistant.

They are countless of what-ifs from those awful days in Dallas.

You just heard from Dave Powers, one of Kennedy's presidential aides and perhaps one of his closest friends.

That was an interview with Charles Corralt,

in which Powers would unequivocally state

...