In light of James Comey's testimony last week, it is abundantly clear that Special Counsel for the Russia investigation Robert Mueller needs to recuse himself from any issues surrounding the former FBI Director. If Mueller, who preceded Comey as FBI Director, were to incorporate issues surrounding his successor in his investigation, then it would constitute an ethical violation through the Department of Justice.
According to Section II(c) of the Department of Justice's Government Ethics Outline:
No DOJ employee may participate in a criminal investigation or prosecution if he has a personal or political relationship with any person or organization substantially involved in the conduct that is the subject of the investigation or prosecution, or who would be directly affected by the outcome.
Section II(c) derives its definition of a "personal or political relationship" from 28 CFR 45.2(c)(2), which states:
Personal relationship means a close and substantial connection of the type normally viewed as likely to induce partiality. An employee is presumed to have a personal relationship with his father, mother, brother, sister, child and spouse. Whether relationships (including friendships) of an employee to other persons or organizations are “personal” must be judged on an individual basis with due regard given to the subjective opinion of the employee.
Mueller and Comey have known each other for years and worked alongside each other during the George W. Bush years when Mueller served as FBI Director and Comey served as Deputy Attorney General under Attorney General John Ashcroft. As Politico reported, when Comey realized that Alberto Gonzales and Andrew Card intended to get an incapacitated Ashcroft to renew the controversial Stellar Wind program, he first contacted Mueller and sought his guidance. In short, not only does Comey have a remarkable professional relationship with Mueller, but he also maintains a strong personal relationship with him.
Comey also once described Mueller as such:
His gift is that he’s decisive without being impulsive. He’ll sit, listen, ask questions and make a decision. I didn’t realize at the time how rare that is in Washington.
Given all of this information, it would obligate Mueller to recuse himself from issues surrounding his friend and former colleague. Robert Barnes elaborated on this issue in his piece in Law Newz:
How can Mueller believe anyone will see his actions as impartial when it requires reviewing all matters of credibility concerning Comey, including possible criminal charge consequences for Comey, when Mueller has been identified as friends of a “unique” “deep” and “close” kind with Comey for more than “a decade”? As important, for the integrity of the legal proceedings, it is essential the public at large see Mueller’s actions as impartial. After all, that is the entire point of a special counsel appointment: a prosecutor above reproach, by action and public perception.
Barnes suggests that if Mueller wishes to be seen as totally impartial in matters surrounding Trump, Russia, and how it relates to the President's decision to terminate Comey, then it would be wise for Mueller to recuse himself from investigating issues surrounding his friend, especially if Comey could get implicated for perjury.