This is less a question than a proposal: That "bootstrapping" be recognized as a logical fallacy. What say ye?

In a murder trial, the weapon has not been found but the prosecution introduced evidence the defendant (D) recently purchased ammunition of the type found in the victim's (V) body. D (white male) and V (black male) were neighbors who had an ongoing boundary dispute.

Okay.

Inference 1 : The ammunition purchase and the boundary dispute are evidence that D killed V.

This is not direct evidence of the hypothesis that the prosecutor is trying to prove (that D killed V), but pretty useful indirect evidence (obviously one would need to account for other factors - how popular that ammo is, whether anyone else had a dispute with V, etc).

Inference 2 (Bootstrapped): Since D is white, and killed V who is black, the (inferred) killing was a hate crime. Therefore, D should receive an enhanced sentence.

non sequitur because a white person killing a black person isn't automatically a hate crime. In fact, any sort of interracial crime does not become a 'hate' crime until intent based on race, religion or ethnicity is proven. Simply killing a person could be down to any number of motivations.

Note that the boundary dispute offers an alternate view of events (two people argued over land, resulting in a fatal shooting - no racial bias/intent required).

So, this practice of bootstrapping is really just tacking on conclusions from premises that don't imply them. Ergo, the argument does not follow (non sequitur).