Pat Smith said she blames Hillary Clinton "personally" for the death of her son Sean, who was killed in the 2012 Benghazi attacks.
"I blame Hillary Clinton personally for the death of my son", an emotional Smith said.
But neither presented any evidence against then-Secretary of State Clinton, who was responsible for security at the Benghazi diplomatic facilities.
For years, Smith said, Clinton has been her nemesis and has denied her information about what happened to her son the night of September 11, 2012.
The penalties for killing a police officer are rightly more severe than those for killing a civilian because police are symbols of the rule of law, she said.
In an hourlong interview with Charlie Rose for CBS News on the opening day of the Republican National Convention, Clinton, the presumptive Democratic nominee, said her rival "has shown that he is risky".
For others, the event gave insight into the major themes we can expect the Republican Party and Donald Trump to harp on throughout the presidential campaign. The ABC/Post survey said 58 per cent of voters say they are dissatisfied with their choice between Ms Clinton, the wife of former President Bill Clinton, and Mr Trump, the one-time television reality show host.
During Smith's speech, viewers on Fox News heard Trump in a telephone interview, where Trump appeared to take some credit for the convention being here in Cleveland.
This entire campaign comes down to a single question: If Hillary Clinton can't give us the truth, why should we give her the presidency? Hillary Clinton is a woman, a mother, and a grandmother of two.
Clinton disputes Smith's account, and fact-checkers at PolitiFact have been unable to resolve the conflict.
Trump wants to help the poor, Melania Trump said.
"That is, unfortunately, part of our political environment right now", she said. "He will make America stronger, not weaker".
Clinton told the crowd she shares the "urgency and the commitment to actually address these issues".
That's when the roll call of states is set to unfold, delivering the delegates to make him the standard-bearer after a rollicking primary season that saw him vanquish 16 rivals.