Start a civil suit.

[no_hypocrisy]

All victims and families. Like OJ.

Get profits for appearances, book deals, donations.

And sue the a-hole who bought and gave him the assault weapon.

Make him pay for each wrongful death and assault.

[Amishman]

1. probably not possible in WI

https://www.ncsl.org/research/civil-and-criminal-justice/self-defense-and-stand-your-ground.aspx

Self-defense laws in at least 23 states (Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Montana, New Hampshire, North Carolina, North Dakota, Oklahoma, Ohio, Pennsylvania, South Carolina, Tennessee West Virginia and Wisconsin) provide civil immunity under certain self- defense circumstances.

I can't find what the circumstances are defined as for WI, but if its like PA, once you are found not guilty in criminal court then a civil case cannot be brought for the same matter.