"Yamagami reportedly told police that he had targeted the former prime minister due to Abe’s affiliation with the Unification Church, which Yamagami blamed for bankrupting his mother
due to its forceful donating practices."
The "mind control" is what the uncle thinks only... there are some who are very devoted to their religion. I did not read anything about the church forcing people to give.
Why didn't this kid kill his mom? She was the one that gave all the money away. And he should have moved out and get a job to pay for his education - I had to do it because my parents weren't educated and held minimum wage jobs.
I think there's more than this donation and the assassin's school concern. Abe is capable of spreading vast influences and Yamagami might have wanted to stop the spread.