Sue Simpson

And then O'Keefe never used his phone again. So the prosecution is using Burgess' testimony to establish a timeline to say that Karen Reid did hit John O'Keefe.

That's right. The defense was on the attack from the jump. Attorney Robert Alessi, he's a new member of Karen Reid's team, hammered Burgess' credibility, accusing him of misrepresentation for saying that he had a bachelor's of science degree when he doesn't.

That's right. The defense was on the attack from the jump. Attorney Robert Alessi, he's a new member of Karen Reid's team, hammered Burgess' credibility, accusing him of misrepresentation for saying that he had a bachelor's of science degree when he doesn't.

This is a strategy, Andrea, that we've seen the defense use before. In the first trial, they went after the credentials of another accident reconstructionist who did not have a bachelor's degree either, and they took him apart. You know, he's clearly hoping that the jury will believe that neither the witness nor his work can be trusted because of this.

This is a strategy, Andrea, that we've seen the defense use before. In the first trial, they went after the credentials of another accident reconstructionist who did not have a bachelor's degree either, and they took him apart. You know, he's clearly hoping that the jury will believe that neither the witness nor his work can be trusted because of this.

You know what amazed me about that? Honestly, Andrea, if it was me, I would have crumpled. But he really stayed calm.

You know what amazed me about that? Honestly, Andrea, if it was me, I would have crumpled. But he really stayed calm.

Well, after Alessi finished his cross-examination, the prosecutor did push back on the idea that Burgess needed a degree to be an expert in the field.

Well, after Alessi finished his cross-examination, the prosecutor did push back on the idea that Burgess needed a degree to be an expert in the field.

Well, Andrea, the prosecution case is so streamlined this time around, the second trial, there are many fewer witnesses.

Well, Andrea, the prosecution case is so streamlined this time around, the second trial, there are many fewer witnesses.

What we have seen is a very strong emphasis on technical, on science, on data, on things like the dwindling battery power in John O'Keefe's cell phone the night he died, showing what the prosecution says that, you know, he lay out on the lawn, he was slowly dying of his injuries and hypothermia.

What we have seen is a very strong emphasis on technical, on science, on data, on things like the dwindling battery power in John O'Keefe's cell phone the night he died, showing what the prosecution says that, you know, he lay out on the lawn, he was slowly dying of his injuries and hypothermia.

And, of course, we have another accident reconstructionist to come in the prosecution's case, and he's expected to lay out exactly how prosecutors believe John O'Keefe was killed. And prosecutors hope that he'll wrap up the case for them.

And, of course, we have another accident reconstructionist to come in the prosecution's case, and he's expected to lay out exactly how prosecutors believe John O'Keefe was killed. And prosecutors hope that he'll wrap up the case for them.

Hi, Andrea. It's a pleasure.

Hi, Andrea. It's a pleasure.

I am a winner. Yay, okay.

I am a winner. Yay, okay.

Yuri Buchanik is a sergeant with the Massachusetts State Police.