If Seth Rich Had Nothing to Do with Wikileaks Why Did Rich Attorneys Just Subpoena Julian Assange and Wikileaks Twitter Messages?

The Clinton murder trail just never goes away.

I don't see anything about such a subpoena. I do see subpoenas for several people who promoted the Seth Rich conspiracy theory. Your idea doesn't really make any sense. The family is suing several people for defamation because they spread the story that Seth was the source of the leaked emails and was murdered for it. If they knew, or suspected, that to be false then they would not be seeking evidence which could undermine their case.

The family is seeking messages from several people who spread this story because they're probably looking for evidence that the people knew or suspected that the Seth Rich story was false. Julian Assange could be a target of the subpoena because he a) would have direct knowledge of where wikileaks got its information from and b) he publicly floated the Seth Rich story to cover for the fact that he got the emails from Russian intelligence.

Its a defemation case. They are suing numerous rightwing pundits for lying about rich.