You're translating the screams of blood from the ground now? While certainly possessing a certain literary flair, the statement lacks a certain...sanity.
I'm struck by the fact that if I were to ever be murdered, some guy, like you, would no doubt be speaking for me and prattling on about my blood is screaming from the ground for vengence, blah blah. In truth, if I am ever murdered, I can only pray now, that I would have the mercy my Lord showed his own murderers when he uttered, "Father forgive them for they know not what they do."
(Denny Crane: "I Don't Want To Socialize With A Pinko Liberal Democrat Commie.Say What You Like About Republicans. We Stick To Our Convictions. Even When We Know We're Dead Wrong.")
Jesus prayed to God to forgive those who were tormenting him. There is nothing in the Bible that advises us to forgive those who harm OTHERS. In fact, false compassion and artifical forgiveness cheapen the real items.
Another point is that when a condemned killer faces his certain death, it gives him a golden opportunity to seriously repent and pray to God for forgiveness.
Putting that in your will would be the only way to let posterity know.