Harvard law professor Alan Dershowitz said Monday that special counsel Robert Mueller is "playing into" President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE's hands after some Republicans raised questions about Mueller's recent conduct, as well as possible bias on Mueller's team.

"Why not seek the warrant? Getting warrants is like getting candy at Christmas. It's very easy to get. And not getting a warrant gives the defense an opportunity to challenge it in court," Dershowitz said on Fox News.

ADVERTISEMENT

Kory Langhofer, counsel to Trump for America (TFA), wrote a letter on Saturday to two congressional committees claiming that Mueller's team improperly obtained thousands of emails from the General Services Administration (GSA), which managed the transition team's email accounts.

Langhofer's letter says the GSA “unlawfully produced TFA’s private materials, including privileged communications, to the Special Counsel’s Office."

Mueller’s office responded on Sunday, denying any wrongdoing. The office did not specify whether it obtained a warrant.

“When we have obtained emails in the course of our ongoing criminal investigation, we have secured either the account owner’s consent or appropriate criminal process,” Peter Carr, a spokesman for the special counsel’s office, said in a statement to The Hill.

Dershowitz added Monday that he believes Mueller has a credibility problem after it was revealed he removed a member of his team who sent anti-Trump text messages.

“He has been conducting a sloppy investigation, and that’s atypical of him,” Dershowitz said. “I’m surprised. When you’re going after the president, you have to be Caesar’s wife. You have to be above reproach. You can’t give the other side any ammunition.”

Mueller has indicted or obtained guilty pleas from four individuals so far in his criminal investigation into possible collusion between the Trump campaign and Russia.

Trump on Sunday told reporters he is not considering firing Mueller.