About 1,100 people have been executed in the United States in the last three decades. Harris County, Tex., which includes Houston, accounts for more than 100 of those executions. Indeed, Harris County has sent more people to the death chamber than any state but Texas itself.

Yet Harris County’s capital justice system has not been the subject of intensive research  until now. A new study to be published in The Houston Law Review this fall has found two sorts of racial disparities in the administration of the death penalty there, one commonplace and one surprising.

The unexceptional finding is that defendants who kill whites are more likely to be sentenced to death than those who kill blacks. More than 20 studies around the nation have come to similar conclusions.

But the new study also detected a more straightforward disparity. It found that the race of the defendant by itself plays a major role in explaining who is sentenced to death.