Delegates from Oregon initially erupted, briefly interrupting his remarks by chanting "No More War!" Other groups around the arena began chanting "Hillary!" More chants of “Love Not War!” and "No More Drones!" broke out before being swallowed by "USA!" from most of the arena.
Meanwhile, Panetta charged on during his speech, hitting Trump for being inexperienced.
"Today, Donald Trump once again took Russia’s side," Panetta said. "He asked the Russians to engage in American politics. Think about that for a moment. Donald Trump wants to be President of the United States...is asking one of our adversaries to engage in hacking or intelligence efforts against the United States of America to affect an election."
"I have worked alongside nine presidents, Republicans and Democrats ... and I can tell you this: There is only candidate for president who has the experience, temperament, and judgment to be Commander-in-Chief and that's Hillary Clinton. This is no time to gamble with our future."
"She is smart. She is principled. She is tough and she is ready. Hillary Clinton is the single most experienced and prepared person who has ever run for President of the United States," he said.
Trump's campaign released a statement in response that attacked Panetta's failure to mention Clinton's use of a private email server while secretary of state.
"It is alarming that Leon Panetta would, through his silence, excuse Hillary Clinton's enablement of foreign espionage with her illegal email scheme and her corrupt decision to then destroy those emails and dissemble her 'private' server to hide her crimes from the public and authorities. He better than most should know how many lives she put at risk," read the statement authored by Trump campaign senior policy advisor Stephen Miller