has an idea that has crossed my mind too: Make the penalty for such crimes utter anonymity.
Thou hast rebuked the nations, thou hast destroyed the wicked; thou hast blotted out their name for ever and ever. The enemy have vanished in everlasting ruins; their cities thou hast rooted out; the very memory of them has perished. But the LORD sits enthroned for ever, he has established his throne for judgment; and he judges the world with righteousness, he judges the peoples with equity. – Ps 9:5-8
There’s something to be said for blotting out the name and memory of such people. Also, self-serving idiots who instantly turn horror like this into dumb culture war narratives so that Team My Tribe can score a point should be banished from the airwaves and sentenced to dig the graves of the victims.
The only response to this is prayer and penance–and cultivation of a culture that does not glorify violence as a quick ticket to fame.