Judson, C. J., Pandell, J. J., Owens, J. B., McIntosh, J. L., & Matschullat, D. L. (1969). A study of the California penalty jury in first degree murder cases. Stanford Law Review, 21, 1296-1497.
Used 178 variables related to defendant, victim, and crime to predict sentencing outcomes. Many weak-moderate associations; controlling for many 3rd variables, blue-collar defendants more likely than white-collar defendants to receive death penalty; victim and defendant race not significantly associated. Reduced set of 25 variables predicted sentence with 88% accuracy.