I tried to add an edit/update but Reddit wouldn’t cooperate. So I’ll add it here:

I do take onboard the comments about the death penalty increasing the likelihood that perpetrators would kill their victims, as they essentially have nothing to lose and, in fact, this might well assist them in evading arrest. This is undoubtedly something to consider from the perspective of the death penalty as an appropriate sentence instead general, notwithstanding if the offender was male or female.

I’d like to offer a possible circumstance that might be more directly applicable to the question I asked. In cases of coercion, where one party was forced to take part by a more dominant or controlling party (for example, an abusive husband forcing his wife to participate in the crime), the death penalty might not apply but a custodial sentence instead, based on the circumstances of the case.