This week is probably not going to be a good one for the FBI director, Kash Patel.

Mr. Patel is set to be grilled by members of Congress in the coming days over concerns about his handling of the investigation into Charlie Kirk’s assassination and questions about files related to Jeffrey Epstein. Mr. Patel was criticized for posting on social media that a “subject” had been in custody in the assassination when in fact there was not. 

President Trump’s FBI director has faced intense scrutiny in recent weeks, including regarding a lawsuit recently filed by former agency officials who were dismissed by Mr. Patel. Three former FBI special agents sued Mr. Patel last week, alleging that he had launched “a campaign of retribution” because the agents refused “to demonstrate sufficient political loyalty.”

Some conservatives, too, expressed anger at Mr. Patel shortly after the assassination. 

Following Kirk’s murder last Wednesday, Mr. Patel traveled to Utah to attend a press conference announcing that the alleged perpetrator, Tyler Robinson, had been arrested. On the day of the attack, however, he left some confused by posting messages to social media that were later found to be premature. 

“The subject for the horrific shooting today that took the life of Charlie Kirk is now in custody. Thank you to the local and state authorities in Utah for your partnership,” Mr. Patel wrote on X just minutes before local FBI officials and Utah law enforcement held a press conference. When those officials spoke to the press, they said that there was no one in custody, and that they were simply questioning a “person of interest.”

Mr. Patel later announced that that person of interest to which he had referred had been released. 

“I’m grateful that Utah authorities have captured the suspect in the Charlie Kirk assassination, and think it is time for Republicans to assess whether Kash Patel is the right man to run the FBI,” conservative activist Christopher Rufo — who was close with Kirk and knows many in the Trump administration — wrote on X. 

“He performed terribly in the last few days, and it’s not clear whether he has the operational expertise to investigate, infiltrate, and disrupt the violent movements — of whatever ideology — that threaten the peace in the United States,” Mr. Rufo added. 

He is set to appear before the Senate Judiciary Committee on Tuesday morning and in front of the House Judiciary Committee on Wednesday, where he is sure to be questioned about the case and the FBI’s role in apprehending the alleged killer. Mr. Robinson’s father turned him into local police in southern Utah after seeing a photo of the suspected killer released by the FBI. 

One former FBI official told the AP that Mr. Patel is likely to get some tough questions during his testimony before senators on Tuesday. “Because of the skepticism that some members of the Senate have had and still have, it’s extremely important that he perform very well at these oversight hearings,” the FBI’s former congressional affairs director, Gregory Brower, told the outlet. 

Mr. Patel seems perfectly aware of his conservative critics. On his official X account, the FBI director has posted or reposted three separate messages in the last 24 hours about how the president is still backing him. 

In an interview with Fox News on Saturday, Mr. Trump praised Mr. Patel. “I am very proud of the FBI,” Mr. Trump said. “Kash — and everyone else — they have done a great job.” Mr. Patel has now shared that article three times since it was published. 

The FBI director could also be questioned about the Epstein files, and how the justice department is planning to send information to Congress. A bipartisan bill in the House that would force Attorney General Pam Bondi to release the files could come up for a vote by early October. 

A Republican lawmaker, Congressman Thomas Massie, says that the House Oversight Committee’s investigation into Epstein does not go far enough because administration officials can simply decide what is and what is not available for release. 

“They’re allowing the DOJ to curate all of the information that the DOJ is giving them. If you’ve looked at the pages they’ve released so far, they’re heavily redacted,” Mr. Massie said at a rally outside of the Capitol earlier this month.