Up next, a music teacher is found dead.

Is it an accident or murder?

They were forensic teams going in and out of the house for days on end.

Lumenall provides some answers.

It just led up like a Christmas tree. It was an hour long.

She didn't have any enemies. That's why it was thought to be an intruder case.

But sometimes friends are more dangerous than enemies.

Secrets that were been kept for so many years

finally caused the whole thing to explode.

Music played an integral part in the lives of Ken Fitzhugh and his wife Christine.

They met as young people and I think they shared a love of music.

That's kind of what got their relationship going.

They married a couple of years after that.

Ken and Christine lived in Palo Alto, California, where they raised two sons.

Christine was a music teacher in the local public school.

Ken was a real estate consultant.

Life was going well for the couple until one day in 2000, when Ken got a call from Christine's school.

Christine had failed to show up for her one o'clock music class.

And this was very unusual. She was very punctual. She has very much of perfectionist.

Ken had no idea where she was.

So he and two co-workers drove to the house to see if she was there.

When they arrived, they found Christine's car in the driveway.

...