Earth's Blood Cry
Middle Eastern tradition holds that a murdered man's blood cries out from the earth demanding vengeance, as Abel's blood cried out against Caine. An ashipu can mold a tablet of clay and a murder victim's blood, and enchant it to scream when the murderer touches it.
System: The magician needs at least one blood point's worth of the murder victim's blood, collected after death (it's no good having someone store a pint as a hedge against the possibility of murder). Once crafted, the magic tablet retains its enchantment for one month, or until the murderer touches it. The tablet cries out only once.