From a previously posted newspaper article:
"Deputy District Attorney Joseph J. Marusak, who already had charged Kopp with intentional murder, then went back to a grand jury and got
an additional charge of causing his death by depraved indifference." (I don't think "impraved" is a word)
I searched several online law dictionaries without much success. However, I did find one reference:
"In Tison v. Arizona, however, the Court eased the 'intent to kill' requirement, holding that, in keeping with an 'apparent consensus' among the states, 'major participation in the felony committed, combined
with reckless indifference to human life, is sufficient to satisfy the Enmund culpability requirement.' "
LINK The cases referenced on this site all deal with the "death penalty." However, as part of the agreement to extradite James Kopp, the U.S. had to stipulate that they would not seek the death penalty.
This doesn't really answer your question. Hopefully a Freeper, who is a lawyer, will add more detail.