You are asking me to prove what has been commonly reported? I'm afraid I cannot prove Podesta said what he said but don't worry, you cannot disprove it either. You should notice, however, that the Rich case has all the marks of a hit job and cover up. The FBI cannot solve the murder and is not willing to discuss eyewitness testimony in the case. The same is true with the DC police and the DNC. They are not wanting the Rich murder to be solved, if their attitudes and actions are any indication.
Furthermore, Mueller never looked into the murder even though Rich was logically accused of being the perswon who leaqked the DNC emails to Assange. Why did Mueller refuse to investigate these published claims about the Rich murder if he was not involved in a coverup of the murder? He was paid millions of dollars to find out who delivered the DNC emails to Assange and he failed because he would not look into the Rich murder.
Here are facts and details and facts the left want to hide under the accepted narrative that the Rich murder cannot be solved and anyone who looks into the murder is a right-wing conspiracy nut, which is a sure sign of conspiracy to cover up the crime.
Vanity Fair: Hillary threatened to “shoot the panda”, Seth Rich’s Handle was “Panda” – The Impious Digest