Co-defendants charged with committing the same crime often receive different punishments, where one defendant may receive a death sentence while another receives prison time.
Approximately two percent of those convicted of crimes that make them eligible for the death penalty actually receive a death sentence.
Each prosecutor decides whether or not to seek the death penalty. Local politics, the location of the crime, plea bargaining, and pure chance affect the process and make it a lottery of who lives and who dies.
Since the U.S. Supreme Court reinstated the death penalty in 1976, 80% of all executions have taken place in the South. The Northeast accounts for less than 1% of executions.