How do you remove old dried blood from a carpet?
Well depending on the color of your carpet, some cleaners will bleach out dark colors. I had good luck with Oxyclean. Follow the directions on the container. But be warned, at first the stain actually turns a darker color as the reaction starts, then it gets lighter as you keep rubbing. I freaked out when a blood stain I removed turned black as ink, but then as I rubbed it faded away.