The fact that an elf was his father's killer was concealed by Acheron's mother and Salek, but Acheron found out when he witnessed Kayn 'dar's memory of witnessing the killing through the pendant.
The fact that an elf was his father's killer was concealed by Acheron's mother. The fact that an elf was his father's killer was concealed by Salek. Acheron found out. He witnessed Kayn'dar's memory of witnessing the killing through the pendant.