Luigi seems to be the guy who justifiably killed that CEO and was definitely framed for murder.

You are very close. Someone can be guilty and also be framed by a corrupt 'justice' system. They can also do something that can be seen more than one way depending on context, like how killing someone could be 1st degree murder, manslaughter, or self defense depending on circumstances.

In this case it is a mix of being seen as self defense and the police not following proper procedure in ways that promote speculation of him being framed. So from my perspective he likely did it, but if he did it was self defense/protecting innocents and the police/prosecution are trying to frame him for a quick and public spectacle to appease the wealthy.