Which component of justice— retribution, incapacitation, deterrence, rehabilitation and reparation [1]—is served by jailing this person?
The only one I see is retribution. Given the families are pursuing damages, the reparation prerogative is better served with him out of jail (and not draining his assets fighting prison time).
[1] https://www.unodc.org/e4j/en/crime-prevention-criminal-justi...