Theories abound about how to explain the Las Vegas murderer. I believe his real motivation was the adoption of and the literal butcher’s thumb application of the world view of anti-Christian atheism which is directly in opposition to the absolute values found in the Christian ethic.
No relativist can begin to judge the equally values-free murderer who would simply ask why their judgment of his actions are any more valid than his own. This is the default position in which liberals are forever stuck because they have ultimately no absolute authority to appeal to outside and beyond themselves.
Christianity stands in opposition to this alien system. Atheism, a defective standard, has flipped truth in favor of man as god, at least for the moment, and pretends the ability to whistle up most any lie to prop up a political viewpoint at the expense of authentic morality.
An additional fatality to this false premise is the destruction of the right to private ownership of firearms. When the liberal speaks from the corner of his mouth and pleads for more “common sense” gun laws he actually means a ban and a little bit more: a strict monopoly on firearms available only to the big government socialist class.