Sexual assault including choking someone to the point of nearly passing out does not have any such mitigating circumstances.

Millions of people live in much more dire conditions and do not commit such heinous crimes.

I think if you have a situation where it is provable that the accused was routinely discriminated against or harmed due to their race an argument could be made for leniency. I don't think choosing to go to a university in an all white town qualifies. If he didn't like the school he could have transferred elsewhere. I don't know the details but considering this school is across the country from where his parents live I would imagine he went there because he got a free ride to play football for them. He chose to go there. He chose to live across the country from his family and in an practically all white community with no immigrants.

I also think it is dependent on the offense. If someone who grew up in poverty and lacks education is convicted of stealing or selling drugs maybe you could make an argument their circumstances led to desperation but I don't think this should come into play when the crime inflicts significant physical harm on others.