President Donald Trump unloaded a series of tweets on Wednesday morning ahead of former special counsel Robert Mueller’s testimony in front of Congress.

President Trump questioned why Mueller did not investigate  2016 Democratic nominee Hillary Clinton and several Justice Department officials.

“Why didn’t Robert Mueller [and] his band of 18 Angry Democrats spend any time investigating Crooked Hillary Clinton, Lyin’ [and] Leakin’ James Comey, Lisa Page and her Psycho lover, Peter S, Andy McCabe, the beautiful Ohr family, Fusion GPS, and many more, including HIMSELF [and] Andrew W?” Trump wrote Wednesday on Twitter.

The president continued, “So why didn’t the highly conflicted Robert Mueller investigate how and why Crooked Hillary Clinton deleted and acid washed 33,000 Emails immediately AFTER getting a SUBPOENA from the United States Congress? She must have GREAT lawyers!”

President Trump also revealed that Mueller denied reports that the president turned him down for the role of FBI director the day before Mueller’s appointment as special counsel in 2017.

“It has been reported that Robert Mueller is saying that he did not apply and interview for the job of FBI Director (and get turned down) the day before he was wrongfully appointed Special Counsel. Hope he doesn’t say that under oath in that we have numerous witnesses to the interview, including the Vice President of the United States!” the president wrote Wednesday on Twitter.

President Trump was also displeased with Mueller’s request that Aaron Zebley, his deputy during the probe, be sworn in as a witness in order to address any questions that he is not able to answer.

“So Robert Mueller has now asked for his longtime Never Trumper lawyer to sit beside him and help with answers. What’s this all about? His lawyer represented the ‘basement server guy’ who got off free in the Crooked Hillary case. This should NOT be allowed. Rigged Witch Hunt!” Trump wrote on Twitter.

Zebley represented former Clinton aide Justin Cooper in 2015 and 2016 in the investigation into former Secretary of State Hillary Clinton’s use of a private email server, according to the Washington Examiner.

“So Democrats and others can illegally fabricate a crime, try pinning it on a very innocent President, and when he fights back against this illegal and treasonous attack on our Country, they call It Obstruction?” Trump tweeted. “Wrong! Why didn’t Robert Mueller investigate the investigators?”

Mueller is now no longer a Justice Department employee. He decided to formally close the special counsel’s office and resigned from the department after he made the first public statement about his Russia probe report in late May.

In the report, the Mueller team concluded that there was no evidence that the Trump campaign colluded or conspired with Russia. The former special counsel said he could not conclude President Trump was innocent of some crimes, but could not name any crime the president committed.

Such a result raised criticisms that Congress is wasting time and taxpayers money on the probe that President Trump frequently calls “Witch Hunt.”