"I didn't want these people to hurt any more kids," Justin said recently of his decision to become a federal witness.

A little more than four weeks after his 19th birthday, Justin became a federal witness.

"The federal witness who died before he could testify," I said.

Soon after, he was granted immunity by the government and became a federal witness.

You were defending your life and the life of a federal witness.

His mission led him to a robotics genius who was a federal witness.

Klein becomes a federal witness, but is given 48 hours before he is taken into custody.

All of them agreed to become federal witnesses.

Mr. Berry was granted immunity and is now a federal witness.

After his racing career he served a 15-year prison sentence for a variety of crimes including drug trafficking and shooting a Federal witness.