Ryan Richards and Mac in “Clean Sweep”

I know what I did to his body is wrong, and I should be punished for that, but... I didn't kill Charlie.

Mac

Well, unfortunately, the science can't confirm that. The damage to the body was so severe that determining a definitive time and cause of death is impossible.

What... what does that mean?

Mac

Well, the D.A. will consider what we can prove, and then decide whether or not to charge you with murder.

Charlie was dead when I lit that fire. You have to believe me.

Mac

For what it's worth... I do believe you. But it's not up to me.