Dylan Roof, Robert Bowers, Dzhokhar Tsarnaev: Biden did not commute death sentences of these three killers; who are they and why didn't he commute their sentences

President Joe Biden commuted the sentences of 37 federal death row inmates, replacing the death penalty with life imprisonment without parole. Yet, three notorious names—Dylann Roof, Robert Bowers, and Dzhokhar Tsarnaev—remain on federal death row.