Melania Trump questions Trump assassination attempt story: 'We need to uncover the truth'

Former first lady Melania Trump questioned the official account of the attempted assassination this summer of her husband, Republican presidential nominee Donald Trump.

Speaking in a dramatically produced 30-second video, posted to social media Tuesday to promote her new memoir, Trump argues there is "definitely more to the story."

She refers specifically to the failure of law enforcement to arrest the shooter Thomas Crooks before the near-fatal shooting of Donald Trump at a campaign rally in western Pennsylvania.

"The attempt to end my husband's life was a horrible, distressing experience," she says on the video. "Now the silence around it feels heavy."

"I can't help but wonder, why didn't law enforcement officials arrest the shooter before the speech?" she said. "There is definitely more to this story, and we need to uncover the truth."

The video ends with an image of her new book, "Melania," and a link to buy copies of it. The book is being released the second week of October.

CNBC has reached out to Donald Trump's campaign to request comment on the statement by his wife, which was posted online hours before her husband was due to debate Vice President Kalama Harris, the Democratic presidential nominee, in Philadelphia.

The Secret Service, which protects Donald Trump and other former presidents, has faced intense criticism for its failure to prevent Crooks from firing during the rally in Butler Township, Pennsylvania, on July 13. Crooks had positioned himself on a roof overlooking the rally site nearby.

Trump's ear was hit by gunfire and one man was killed, former fire chief Corey Comperatore. Several other people were injured before Crooks was fatally shot by the Secret Service.

Crooks was identified by police as suspicious near the rally because "he was milling about and he stood out to them because he never made his way to a point of ingress to the venue," Pennsylvania State Police Col. Christopher Paris said at a House Homeland Security Committee hearing on July 23.

Crooks was later spotted by police carrying a range-finder, according to Paris.

He fired off rounds from a rifle after a Butler Township police officer hoisted himself up to the edge of the roof, only to see Crooks pointing a gun at him.

Kimberly Cheatle, who had been the Secret Service's director at the time of the shooting, resigned on July 23, a day after members of a House of Representatives committee lambasted her and the Secret Service over their handling of the shooting.