Are you old enough to remember a prisoner named Gary Gilmore? He was convicted of a double homicide and executed by firing squad in Utah. The unique aspect of his story is that he was the first person to be put to death in the US after capital punishment was reinstated in 1976. (1)
In 1972, the US Supreme Court (SCOTUS) decided that the death penalty violated the Eighth Amendment of the Constitution because it was considered cruel and unusual punishment. This ruling was based on the grounds that the states imposed the death penalty in "arbitrary and capricious ways" particularly with respect to race. In 1976, however, SCOTUS reversed the decision and allowed states to impose the death penalty but required the states to develop specific guidelines around its imposition. (1)
Not much has changed in the 40+ years since the reinstatement of the death penalty. Racial disparity is alive and well in the United States. African Americans make up approximately 13% of the general US population but are 42% of the inmates on death row and 35% of those executed. Additionally, if the victim is white the killer is much more likely to receive the death penalty.