Secret Service ramped up security after intel of Iran plot to assassinate Trump; no known connection to shooting. CNN

US authorities obtained intelligence from a human source in recent weeks on a plot by Iran to try to assassinate Donald Trump, a development that led to the Secret Service increasing security around the former president, multiple people briefed on the matter told CNN.

There’s no indication that Thomas Matthew Crooks, the would-be assassin who attempted to kill the former president on Saturday, was connected to the plot, the sources said.

The existence of the intelligence threat from a hostile foreign intelligence agency — and the enhanced security for Trump — raises new questions about the security lapses at the Saturday rally in Butler, Pennsylvania, and how a 20-year-old man managed to access a nearby rooftop to fire shots that injured the former president.

A US national security official said the Secret Service and Trump campaign were made aware of the threat before Saturday’s rally.

“Secret Service learned of the increased threat from this threat stream,” the official told CNN. “NSC directly contacted USSS at a senior level to be absolutely sure they continued to track the latest reporting. USSS shared this information with the detail lead, and the Trump campaign was made aware of an evolving threat. In response to the increased threat, Secret Service surged resources and assets for the protection of former President Trump. All of this was in advance of Saturday.”

The Trump campaign would not disclose whether it was made aware of the Iran threat. “We do not comment on President Trump’s security detail. All questions should be directed to The United States Secret Service,” the campaign said in a statement.

Secret Service officials have warned the Trump campaign repeatedly against holding outdoor rallies, which pose greater risks than events to which the agency can better control access, people briefed on the matter said. The warnings have been more general in nature, the sources said.

“The Secret Service and other agencies are constantly receiving new potential threat information and taking action to adjust resources, as needed,” Anthony Guglielmi, an agency spokesman, said on Tuesday. “We cannot comment on any specific threat stream, other than to say that the Secret Service takes threats seriously and responds accordingly.”

At one point during this election cycle, the campaign stopped holding spontaneous off-the-record events where guests weren’t swept by Secret Service beforehand due to security concerns, a source familiar with the matter told CNN.

The FBI, which is conducting the investigation into Saturday’s shooting, declined to comment.

NSC spokesperson Adrienne Watson said there’s no known link between shooter Thomas Matthew Crooks and anyone else at the moment.

“The investigation of Saturday’s attempted assassination of former President Trump is active and ongoing. At this time, law enforcement has reported that their investigation has not identified ties between the shooter and any accomplice or co-conspirator, foreign or domestic,” Watson said.

The Permanent Mission of the Islamic Republic of Iran to the United Nations denied there is an Iranian plot to assassinate Trump.

“These accusations are unsubstantiated and malicious. From the perspective of the Islamic Republic of Iran, Trump is a criminal who must be prosecuted and punished in a court of law for ordering the assassination of General Soleimani. Iran has chosen the legal path to bring him to justice,” a spokesperson for the mission told CNN, referencing Qasem Soleimani, the commander of the Iranian military’s Islamic Revolutionary Guard Corps, who was killed by a US airstrike at Baghdad International Airport in January 2020.

CNN’s Fareed Zakaria pressed Iran’s acting Foreign Minister Ali Bagheri Kani on the alleged Iranian assassination plot, asking in an interview if the plot was in retaliation for Soleimani’s killing, which took place during the Trump administration.

“I told you explicitly that we would resort to legal and judicial procedures and frameworks at the domestic level and international level in order to bring the perpetrators and military advisers of General Soleimani’s assassination to justice,” Kani told Zakaria in an interview that will air Sunday on CNN’s “Fareed Zakaria GPS.”

Pressed further if that meant not using violent measures, Kani said, “We will only resort to Iranian and international legal and judicial procedures.”

“Until now, we have done it, and this is our right and of course we will continue it. And the Americans openly said that, that they assassinated the senior Iranian military commander. So it is our natural right in order to follow this issue, and those who are accused in this case, they should be brought to justice in a — in a just court,” Kani said.

Trump and the Republican vice presidential nominee, Sen. JD Vance of Ohio, will hold their first official campaign rally together on Saturday at an indoor arena in Grand Rapids, Michigan, the campaign announced Tuesday.

Iran has repeatedly vowed revenge for the US military’s killing of Soleimani. And former senior Trump administration officials who worked on national security have had tight security since leaving the government.

In August 2022, the Justice Department announced criminal charges against a member of the IRGC for allegedly trying to orchestrate the assassination of John Bolton, who served as Trump’s national security adviser. US prosecutors said the plot against Bolton was “likely in retaliation” for Soleimani’s assassination.

Former Secretary of State Mike Pompeo was also a target of the Iranian assassination plot, according to a federal law enforcement source familiar with the investigation and a source close to Pompeo.

Trump’s former national security adviser, Robert O’Brien, had a US government security detail due to threats from Iran, like Pompeo and other former Trump officials, but that detail was dropped last summer, according to sources familiar with the matter. O’Brien is now paying for his own private security detail, sources said. Lawmakers were not given a specific reason for the decision, which led to frustration. O’Brien did not respond to a request for comment.

Bolton still has his Secret Service detail.

For months, law enforcement officials have been concerned about the persistent threat of Iran potentially attempting to assassinate former Trump officials and the former president himself, according to multiple sources familiar with the matter. But the recent intelligence suggested a significant uptick in the threat, the sources told CNN.

Warnings about that operational planning have coincided with a noticeable surge of online messaging from Iranian accounts and state-backed media mentioning Trump, which has raised security concerns among US officials, one of the sources told CNN.