Agreed, I have a hard time imagining insanity when afterwards they seem sane enough to concoct stories. Elaborate excuses, even interviews before the body is found. I always tend to (want to) think, when a child is involved, that the parent/adult didn't really mean it, as though it were an accident.
But with this chick, Watts, Todt, and dozens more, it's just evil, heinous, a result of many conscious decisions, not just one fly off the handle mistake. I realize Watts confessed, and Todt didn't claim insanity.
There's Andrea Yates then there's Leticia.