Taking homicide as an example (a crime more likely than most to result in a trip to death row), the most recently available data (2019) [1] shows that 56% of perpetrators were black. That's quite a feat for 13% of the population!

If anything, that only 42% of those on death row are black may be indicative of a racial bias in their favour.

[1] https://ucr.fbi.gov/crime-in-the-u.s/2019/crime-in-the-u.s.-...