I guess I don't understood why this has to be a national issue. I suppose you could consider it ageism...discrimination against the very young, and make age a protected category like race. But, to the extent it is just normal homicide, it would seem to be a state issue, to be defined by the state legislatures just like they define every other homicide, with varying degrees of intent, extenuating circumstances, etc. That would clearly not be a national issue...unless people are crossing state lines, in which case Congress can have its say.