WASHINGTON -- After CIA director Gina Haspel briefed a handful of senators Tuesday about U.S. intelligence related to the murder of dissident writer Jamal Khashoggi, lawmakers said they were even more confident that Saudi Crown Prince Mohammed bin Salman was directly involved in the brutal assassination. "There's not a smoking gun — there's a smoking saw," Republican Sen. Lindsey Graham told reporters after the classified meeting.

"I went into the briefing believing it was virtually impossible for an operation like this to be carried out without the crown prince's knowledge," Graham added. "I left the briefing with high confidence that my initial assessment of the situation was correct."

Sen. Bob Corker, an outspoken Republican critic of President Trump and his response to Khashoggi's killing, stressed, "If the crown prince went in front of a jury, he would be convicted in 30 minutes." Asked by a reporter if it would be a murder conviction, Corker replied "yes."

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Mr. Trump has repeatedly defended the Saudi government in the wake of the Khashoggi killing in October. In November, the president said that bin Salman may have had no knowledge of the killing, and in any event the U.S. relationship with Saudi Arabia should not be jeopardized.

"All evidence leads back to the crown prince" Republican Sen. Richard Shelby told reporters as he left the briefing Tuesday. Two senators present told CBS News that Haspel did not share with lawmakers the audio tapes from the day Khashoggi was killed and reportedly dismembered inside the Saudi consulate in Istanbul, Turkey. Secretary of Defense James Mattis has said the U.S. does not have any such tapes in its possession.

The CIA chief briefed the leaders of committees and subcommittees with interests in national security — including the Senate Intelligence, Foreign Relations and Appropriations Committees. Senate Majority Leader Mitch McConnell and Minority leader Chuck Schumer were also present. In a statement issued after the briefing, Schumer called on Haspel to brief the entire Senate "without delay."

Republican Sen. Rand Paul said that he couldn't even have asked for an invitation to the briefing because he only found out about it from the media. "Intelligence is only given to a few people within our system," Paul said Tuesday. "That's more like an oligarchy." Democratic Sen. Tim Kaine, who was also not in the meeting, said the White House was "frightened to let senators have access to this intelligence briefing."

Haspel's absence at a closed-door briefing on Saudi Arabia last week rankled key lawmakers. Soon after that briefing, led by Secretary of State Mike Pompeo and Mattis, senators voted overwhelmingly to advance a resolution to cut American military assistance to Saudi Arabia in its war in Yemen.

Both Mattis and Pompeo stressed after their briefing last week that U.S. intelligence did not suggest there was a direct connection between the crown prince and the order to kill Khashoggi.

"There is no direct reporting connecting with the crown prince to order the murder of Jamal Khashoggi," Pompeo said to reporters last Tuesday.

"I have seen all the intelligence we have," Mattis said on Saturday at the Reagan National Defense Forum in Simi Valley, California. "Right now we do not have a smoking gun."

Corker called the difference between Haspel's briefing on Tuesday and the one led by Pompeo and Mattis last week "darkness and sunshine."

Although he denounced the Trump administration for sending the heir to the Saudi throne a "message" that "you can go around killing journalists," the retiring Tennessee senator questioned the effectiveness of a resolution sponsored by independent Sen. Bernie Sanders designed to end American military aid to the Saudi-led coalition waging a bloody war in Yemen.

"The Yemen resolution gets into a war powers situation. The administration can easily turn the light back on and say we are not involved in hostilities," he said.

Senate leaders are currently debating among themselves how to proceed with the resolution and if any amendments should be added. If allowed, amendments could water-down the resolution to the point where it is mostly symbolic.

One of the Democratic backers of the resolution, Democratic Sen. Chris Murphy, told reporters on Tuesday a decision on the process could extend into next week.

Khashoggi's murder in October has opened a rift between the Trump administration and some of its most consistent supporters in Congress — including Graham, who threatened last week to withhold key votes until he received a briefing from Haspel.

The CIA has assessed that bin Salman, known as MBS, ordered Khashoggi's killing, based mainly on an understanding of how the kingdom operates and the proximity of several members of the team involved to the prince, officials told CBS News. But the Saudis have denied he was involved in the assassination and instead blamed former deputy intelligence chief Ahmed al-Asiri, who they said last month was the highest-ranking official to authorize the attack.

In November, the Trump administration announced sanctions against 17 Saudi nationals for their alleged involvement in Khashoggi's murder. Saoud al-Qahtani, a close aide to the crown prince, was designated as a sanctions target, but neither the crown prince nor Asiri were on the list.

Sarah Horbacewicz contributed to this report.