Looking into motivation is cool, instrumentaling it before knowing it isnt. I feel like him doing that to his family hints to more personal motifs than political. Yet the politicians were like mustve been associated with the other party.

That overshadows the real problems here: why does aperson so unstable have access to guns? He lived with his family, probably unable to move out even if he wanted. This can bear a lot of conflicts/pressure on a young man. But lets not look at problems in the social system, rather use it for party politics - win win i guess.