The analysis used an empirical model to examine the comparative proportionality of Missouri cases and concluded that defendants have been executed whose sentences were disproportionate. However, the Missouri Supreme Court has affirmed 97 cases and reversed only 1 sentence. The Court appears to use comparative proportionality review in a formalistic and mechanical manner that does not result in a meaningful review process. A State's ineffective use of comparative proportionality review raises jurisprudential issues. The process could be improved by using a larger pool from which to take comparison cases, examining more evidence than a common sentencing factor, and using a frequency approach for the case comparison method. These approaches would provide a framework for a meaningful proportionality review. The Eighth Amendment does not require comparative proportionality review, but an inadequate process should be subject to constitutional challenge. Tables, footnotes, and appended list of Missouri laws on aggravating and mitigating sentencing factors