He's saying: "I stopped being a Christian. Then I became a murderer."
That's a testimony of a certain kind in itself.
It’s possible he got saved, but then the devil, associated with the entertainment and glitz, weighed in on him and he was not prepared for it.
Being an evangelist has its own risks. If I became a good rock and roll evangelist and then got secular come-ons, could I refuse them in spite of the worldly riches they might offer? I hope I could.