Their thesis is simply stated. A vastly disproportionate number of federal death sentences come from counties with high minority populations that are located in districts that are heavily white overall. Think diverse urban cores surrounded by lily-white suburbs. Given that federal juries are typically drawn from the entire district, this means that capital trials in these districts are apt to involve minority defendants being judged by white-dominated juries. Having minimal racial diversity on the jury means that black defendants have little protection from the unconscious racial biases that most of us carry around. This, in turn, drives both the racial and geographic disparities in federal death sentences.
The patterns are striking.
For instance, both federal districts in Missouri display the racial demographics that are of interest to Cohen and Smith (racially diverse urban county surrounded by heavily white suburban counties), and Missouri has returned more federal death sentences than New York, California, and Florida combined (p. 436). In fact, Cohen and Smith contend that all eight of the districts that have returned more than two federal death sentences exhibit pronounced county-district racial disparities.
