“As someone else has posted: A prosecutor may immediately seek an indictment, if someone exercises their right to an examining trial. But, that means the prosecutor must “show their hand” to a grand jury, and will have to show the evidence against Clendennen, individually. “
Only if he is indicted. That is standard discovery process.
No, a grand jury has the power to subpoena witnesses and review the evidence. Whether they choose to do so is up to them.
But, as Sol Wachtler (in)famously claimed: "district attorneys now have so much influence on grand juries that "by and large" they could get them to "indict a ham sandwich."
It will be interesting to see if this grand jury takes their job seriously, or just rubber-stamps the indictments.