It’s complicated…. I don’t think he was the one who physically killed her but he ordered the attack on the village?
He killed her. There's a scene in the novel where one of his guards say something like "no one else would have done such a thing", as in, no one else within the soldiers would do such a grotesque thing like killing someone so violently like Garon killed his mother.
The context was, Roha was asking the said guard (don't remember his name, it's the long haired one out of the three) about the person who killed his mother. He had hopes that it wouldn't be Garon. And the guard, not to say directly it was him (Garon), said what I posted in the comment above. Was his way of saying "it was him".
Nooooo .·´¯`(>▂<)´¯`·.
Oh please, please let it not be Garon that killed Raon's mother . ┗( T﹏T )┛ if he is ...... I'ma turn a blind eye, ehehehehee