"Finally, with respect to the Commission's conclusions in Part IV(C)(4) that Mr. Garza's rights to due process and a fair trial under Articles XVIII and XXVI of the American Declaration were violated, we note that these conclusions are in conflict with jurisprudence based on the Eighth Amendment to the U.S. Constitution. This jurisprudence requires the provision of all relevant information to a capital jury before it makes a sentencing determination. Indeed, the rationale on which the Commission recommends invalidating Garza's death sentence was presented to the appropriate federal courts in collateral review and rejected by them as not affording a basis for relief".