the book says only the passive of gra/fw carries the meaning indict, but then why is a future passive participle taking the genitive of charge construction? does the passive carry the meaning indict as well or is this a mistake in the book?
I think upo tou dhmou is an agent. “In order to be charged by the people…”. Graphesomenos is future in middle voice. The letter eta after the -ph- appears in some intransitive forms.