Patricia Smith speaks at the Republican National Convention in Cleveland, Ohio, July 18, 2016. (AP)

(CNSNews.com) – In her speech at the Republican National Convention in Cleveland, the mother of diplomat Sean Smith, who was killed in the radical Islamic terrorist attack in Banghazi, Libya on Sept. 11, 2012, explained that, at her son’s coffin ceremony, then-Secretary of State Clinton looked her in the eye and lied to her, blaming Sean Smith’s death on an anti-Muslim video posted on YouTube.

“She lied to me and then called me a liar,” said Patti Smith on Monday. At the Sept. 14, 2012 coffin ceremony at Andrews Air Force Base, attended by Clinton, President Obama, and other officials, Secretary Clinton “looked me squarely in the eye and told me a video was responsible,” said Smith.

The video claim, which was pushed by the State Department and the White House for several weeks leading up to the November 2012 presidential election, has been proven to be false.

The House Select Committee on Benghazi confirmed that then-Secretary Clinton told the prime minister of Egypt on Sept. 13, 2012: “We know that the attacks in Libya had nothing to do with the film. It was a planned attack – not a protest.”

Concerning the attack and the claims made by Hillary Clinton, Patti Smith further said in her speech, “The very next day [Sept. 11], he [Sean Smith]was murdered by radical Islamic terrorists. To this day, I don’t even know why a computer guy like Sean was sent to Benghazi.”

“That night, we lost sons, brothers, fathers, and husbands,” said Smith. “We lost four brave Americans who made the ultimate sacrifice for the country they chose to serve. And the American people lost the truth.

“For all of this loss, for all of this grief, for all of the cynicism, the tragedy in Benghazi has wrought upon America, I blame Hillary Clinton,” said Smith. “I blame Hillary Clinton personally for the death of my son.”

“In an email to her daughter [Chelsea Clinton] shortly after the attack, Hillary Clinton blamed it on terrorism,” said Smith. “But when I saw Hillary Clinton at Sean’s coffin ceremony, just days later, she looked me squarely in the eye and told me a video was responsible.”

Diplomat Sean Smith, murdered by radical Islamists in Benghazi, Libya, Sept. 11, 2012. (AP)

Since then, I have repeatedly asked Hillary Clinton to explain to me the real reason why my son is dead,” said smith. “I’m still waiting. Whenever I called the State Department, no one would speak to me because they say I am ‘not a member of the immediate family.’ Sean is my son.”

Patti Smith continued, “Hillary Clinton is a woman, a mother, and a grandmother of two. I am a woman, a mother, and a grandmother of two. How could she do this to me? How could she do this to any American family?”

In the attack on the U.S. compound in Benghazi, four Americans were murdered: Ambassador Chris Stevens, Diplomat Sean Smith, and two former Navy SEALs, Glen Doherty and Tyrone Woods.