So, a 39 year old man living with his mother gets so angry with her because she charges him rent that he decides to kill her. He shot her with a crossbow, she still managed to call for help but died in the hospital.
It's people that kill people, not crossbows, not guns, not motorvehicles ... people.
And there's some sacry people out there ... his own mother?! You don't think people like that will gladly continue to kill eachother long after guns (and crossbows) have been banned?