ST. LOUIS — Attacking rival Hillary Clinton again for using a private email server, Donald Trump told his rival he would appoint a special prosecutor to go after her if he’s elected president, just one of many barbs in what proved to be an incredibly negative debate.

“I hate to say it, but if I win I’m going to instruct my attorney general to get a special prosecutor to look into your situation,” Trump said. “Because there have never been so many lies, so much deception.”

Trump said that Americans are “furious” that the FBI declined to recommend prosecution after investigating Clinton’s use of a private email server while she was secretary of state.

The stage was set for an acrimonious debate before the two candidates even set foot in the town hall meeting, and the pair kicked it off by skipping the standard handshake.

Slideshow: Body language: Hillary Clinton and Donald Trump face off for their second fiery debate >>>

The candidates remained visibly irritated with each other, with Trump frequently interrupting and talking over Clinton. “I know you’re big into diversion tonight, anything to avoid talking about your campaign and the way it’s exploding and the way Republicans are leaving you,” Clinton retorted.

The real estate magnate also implied that Clinton did not legitimately win the Democratic primary, saying she beat Sen. Bernie Sanders, “but not fair and square in my opinion.” Trump also said he was surprised to see Sanders “sign on with the devil,” presumably referring to Clinton as Satan.

At one point, Clinton said it was good that someone with Trump’s temperament was not in charge of U.S. law. “Because you’d be in jail,” Trump interjected. Clinton ignored the comment.