Ahh, so you're blissfully unaware that the statistics you've provided in no way necessitate racism within the Louisiana criminal justice system.
Let me give you another hypothetical example to illustrate how and why you're wrong:
Suppose there are 200 adult males with the family name "Smith" living within a given jurisdiction. And that there are 200 adult males with the family name "Jones" living in the same jurisdiction.
Suppose now that, for complex socio-economic reasons, 60 adult males with the family name "Smith" commit serious crime over a certain period, while only 30 adult males with the family name "Jones" commit serious crime over the same period. And suppose for a moment that law enforcement has a perfect record in catching, prosecuting and imprisoning all perps of serious crime.
With me so far?
Now, someone who knew no better might announce "AHA! There are equal numbers of "Smith" and "Jones" adult males in this jurisdiction, yet there are twice as many Smiths in prison! This shows that the criminal justice system in this jurisdiction is discriminatory towards the "Smith" population compared with the "Jones" population!"
Hope that helps.
ETA: NB I'm not stating that there necessarily is NO institutionalised racism within the Louisiana criminal justice system. And I will also point out that the comparatively lower average socio-economic position of black people in the US, particularly in inner cities and Southers/Bible Belt states - which manifests itself in proportionately higher rates of crime among black populations - is the product of historic and (to at least some extent) current racist attitudes towards black people. But my point is that it's impossible simply to show the imprisonment rates per head of population and claim that this necessarily proves racism. It's a hell of a lot more complicated than that.
The National Registry of Exonerations has recently (September, 2022) published online a report, Race and Wrongful Convictions in the United States 2022*.
In the US, the percentages of Black men exonerated due to a wrongful conviction of either murder or rape, and indeed for all crimes except white collar crimes, have been larger than the percentages of white men exonerated due to a wrongful conviction for those crimes. The number of Black and white men exonerated due to a wrongful conviction for rape has decreased in recent years apparently because of the effectiveness of DNA identification.
Pertinent to the Knox - Sollecito case, the DNA identification of Guede as the murderer/rapist of Kercher appears to be reliable and is consistent with all other evidence against him. The apparent failure of the Italian police and prosecutor to not have DNA tested the putative semen stain on the pillow, marked by Guede's shoe print, and found under her body, is puzzling. This apparent semen stain was called to the attention of the Massei court by a defense expert who had detected it using CrimeScope.
* https://www.law.umich.edu/special/exoneration/Documents/Race Report Preview.pdf