The first clause you quote is dependent on the killing being purposeful. Intentionally killing someone during the commission of another felony elevates the charge to murder one. The second half deals with the conditions under which unintentional homicide can be elevated to murder one. FWIW, were it a crim law exam, I think you could score points by calling it a purposeful murder via depraved heart, but that’s at common law, and I don’t believe DC has the equivalent.

That said, given the history of violent crimes, the concurrent felonies, etc, and that he dragged the victim before pinning him against the tree, I’m disappointed, but not surprised, that the AUSA didn’t either go for a longer sentence on the manslaughter charge or even try for murder two.