Of course Breitbart claims that. Go to a prison and you'll see all the inmates claiming innocence. If this is the best argument you can up with I'd advice to not bring it up at all.
How many of those involved plea deals? If you can't afford legal representation, you won't get anything that deserves to be called that in the US. If you're then also faced with the ridiculously high sentences you can get in the US, you'll no doubt find yourself pleading guilty to a lot of things to get a deal.