From the Epistle of the Same Nicholas, to Rodulph, Archbishop of Bourges, A.D. 864

Response V. Concerning those who hold their stepchildren for confirmation before the bishop, that is, who support over themselves the sons of their wife by a prior husband, while they are chrismated by bishops: if it is done through ignorance, as you assert, although it is a sin, nevertheless it must not be punished to the extent of separation of the marriage.

Response VI. Killers of their own spouses, when you do not add "adulteresses" or something of this sort, what else are they to be held except murderers, and through this to be reduced to penance? To these marriage is entirely denied, except adolescents, concerning whom the twenty-fifth rule of the decretals of blessed Leo (namely, in the Dionysian collection; it is the one which we gave above from the epistle to Rusticus, Decree XIII), rather the indulgence, is to be observed.

The crime of a killed spouse is an impeding impediment from marriage for all except adolescents.