Lester Holt

Is that a lethal amount of cyanide?

Yes.

Prosecutor Lisa Pellegrini said the defendant thought he was so smart, fooling his wife and then everyone else by using a poison he assumed was untraceable.

Standing and looking at the jury, points to Ferrante.

That man right there was one blood test away from the perfect murder.

Murder responded the defense.

What murder?

Robert Ferranti, it said, did not commit a crime because there was no crime.

I said as forcefully as I could, we don't believe and we will never believe that Autumn Klein died from cyanide.

The defense was attacking the cornerstone of the Commonwealth's case.

That blood test with its lethal reading of cyanide could never be trusted, it said.

There's no way that the result is reliable.

Throw it out.

Yes.

Because, he said, the lab initially screwed up with that 3.35 calculation.

It only caught its error months later, correcting the level to 2.2, a still lethal amount of cyanide in Autumn's blood.

It certainly raises a real issue of its credibility.

And gives the defense something to work with.

Absolutely gave the defense a lot to work with.

Far more reliable, argued Ferrante's attorneys, was another test done in the weeks after Autumn's death.