The sort of party incurring a charge (6)
I believe the answer is:
guilty
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for guilty that I've seen before include "Responsible for a crime" , "Justly charged" , "Responsible for a reprehensible act" , "Jury verdict - the accused did it" , "(Found) responsible for offence" .)