Seth Rich was murdered shortly after Assange announced he had obtained a trove of DNC emails showing dirty DNC secrets. That theft of DNC emails enraged Hillary and her campaign team. What do we know about Seth Rich? He was a Sanders supporter who was offended by the crooked way Hillary and the DNC stacked the deck against Bernie Sanders. What does Rich prove?
Rich proved the democrats lied about the emails, Trump, and the involvement of the DC police and the FBI in the coverup of the murder. The FBI lied about having Rich's computer. The DC police claimed Rich was murdered on the street in a robbery, but the DC police did not report that someone broke into Rich's apartment and stole his computer. When asked about Rich's computer the FBI lied, claiming it did not have it. The democrats claimed Trump colluded with Russia to steal the emails, but that was proven to have been a deliberate lie. Robert Mueller was hired to get to the bottom of the email theft but he never found out who stole the emails and he never looked into the Seth Rich connection to the case in spite of Assange suggesting it was Rich who exfiltrated the emails.
Rich proves the democrats lied about Rich and his murder and then lied about Trump, and that proves the democrats colluded to lie about what really happened in the exfiltration of the emails.