Mike Boettcher

I'm glad. Three generations of Karen's family are here today. Her sisters, Rosemary Silkwood Smith and Linda Silkwood Vincent, along with her son, Michael Meadows. And for the first time, we're joined by Karen's daughters, Christy Riddles and Don Lipsy. Don's 20-year-old daughter Riley is sitting by her mom.

Steve begins with the indisputable facts of the accident. That Karen's car collided with the cement wall of that culvert. The moment of impact. So this is her car. It's taken. He displays a photo of the front end of Karen's tiny white Honda, jagged and crumpled. The hood is collapsed toward the steering wheel like a crushed soda can.

What happened in the moments after the car drove off the road, before it hit the wall? And the question we're all wondering, what caused Karen's car to leave the road in the first place?

Steve and his team looked for signs that Karen might have been trying to regain control after she left the road. Was she steering or braking? He found signs of both.

That would set up the next sequence Steve is looking at. After Karen's car hit the wall and came to a rest, its nose was pointed toward the roadway.

Then there's the question of speed. The speed limit on the highway was 55, and Steve believes it's a reasonable assumption that she was going the speed limit. The alternative would be that she was drowsy or sedated and driving slower than the speed limit. Pipkin calculated by the time Karen hit the wall, she was going 30. Steve says that matches their modeling too.

So the drop in speed after leaving the road to Steve, that indicates the driver took action.

So Karen was awake at the moment of impact. That's the opinion of one expert using the latest in accident reconstruction technology. The idea that Karen was asleep, maybe even in a stupor, as law enforcement once said, that doesn't necessarily check out. And Steve's findings challenge at least one theory that placed the blame for the accident solely on Karen Silkwood.

The Oklahoma Highway Patrol didn't have any comment on the new assessment, and they told us there are no plans to reopen the investigation.

Steve has created simulations of three possible scenarios. In one, the car veers off the road to the right, then overcorrects to the left and loses control.

These are both single-car accidents. But what we've all been waiting for Steve to tell us about is the bumper.

It's not what I expected. It's a nice moment, but looking at the rest of the photo, Steve breaks with his old mentor. He doesn't see what Pipkin saw in these stents.

So Steve thinks it's unlikely that these dents were created by another car, what he poetically refers to as a phantom vehicle. That's a vehicle that's alleged to have been present, but leaves behind no physical evidence. But he doesn't totally dismiss the possibility of a phantom vehicle. He zooms in on the dents.

In the simulation, the phantom vehicle sideswipes Karen's car on the driver's side.

Steve actually looked to see if he could find a car that would have been on the road in the early 1970s that had a bumper low enough to cause the kinds of dents we see in Karen's left rear bumper and fender.

I've always said we follow where the facts lead us. I was convinced that a close-up look at the bumper was going to unlock this thing. But in the end, that's not what I was hearing from Steve.

Steve says even if a phantom vehicle didn't hit her or didn't hit her hard enough to push her off the road, there's still the possibility that Karen was startled and then overcorrected. The intimidation factor.

So what does it all add up to? Steve says there's no evidence to definitively prove or disprove the presence of a phantom vehicle.

Two hours later, Steve pressed pause on his PowerPoint and opened it up for questions and reactions. People's faces were drawn. This didn't seem to be the definitive closure we were hoping for. There was this uncomfortable pause where no one said anything.

So maybe it was something else. Then Karen's daughter, Christy Riddles, jumped in. She asked a question I think a lot of us had.