Since his re-election, President Donald Trump has increasingly involved himself in the operations of the Justice Department, intervening in investigations and prosecutions that have traditionally remained independent from White House influence. This heightened interference has generated significant turmoil within the department, with recent developments underscoring the risks posed by the president’s direct involvement.

Last week, these tensions came into sharp relief through a series of high-profile episodes. On Wednesday, court filings from lawyers representing former FBI Director James B. Comey revealed that Secret Service agents who interviewed Comey about a cryptic photograph he posted were instructed to promptly share a summary of the interview with Mr. Trump aboard Air Force One. The image, which featured seashells arranged to read “86 47,” became a focal point of the president’s attention during the flight, with the White House reportedly eager to use the agents’ notes as part of an upcoming media event. This level of presidential engagement with the details of a sensitive investigation raised concerns about improper interference. Comey’s legal team argued the incident was evidence the Justice Department’s criminal charges against him—for alleged threats against Mr. Trump—were retaliatory, which, if substantiated, could lead to dismissal of the case.

Another case affected by Mr. Trump’s involvement involved David Hearn, a former Olympic canoeist indicted last month for vandalizing the Lincoln Memorial Reflecting Pool, a site of personal importance to the president. U.S. Attorney Jeanine Pirro, who brought the charges, had previously emphasized the case as a presidential priority. However, late Friday, Pirro filed a court document stating that new information indicated construction defects, not vandalism, caused the damage to the pool’s lining. Despite this development, President Trump publicly criticized Pirro, calling her judgment into question and reaffirming his belief in Hearn’s guilt. Legal experts suggest the collapse of the prosecution, combined with the president’s persistent assertions, could bolster arguments that the case was politically motivated and filed in bad faith, potentially enabling Hearn to seek reimbursement for his legal expenses.

The president’s intervention also extended to the confirmation process of his nominee for attorney general, Todd Blanche. Blanche, who previously served as Mr. Trump’s personal lawyer, faced skepticism from Republican senators John Cornyn and Thom Tillis, particularly over a $1.8 billion compensation fund and tax protections linked to a settlement of Mr. Trump’s IRS lawsuit. Throughout the week, Mr. Trump sent mixed signals, at times threatening to withdraw Blanche’s nomination and at other times reiterating support for the compensation fund, which Blanche had acknowledged was effectively defunct. This inconsistency frustrated senators, with Tillis expressing public disappointment that the nominee’s approval was at risk due to the president’s erratic stance. A breakthrough emerged late Sunday when Blanche shared documents formally rescinding the compensation fund and clarifying the tax arrangements after negotiations with senators. By Monday, Mr. Trump distanced himself from the revised plan, stating he had not reviewed the details but continued to support Blanche.

Legal analysts and former Justice Department officials emphasize that presidential intrusion into active investigations and prosecutorial decisions disrupts the department’s conventional autonomy and can undermine the rule of law. The recent incidents illustrate how Mr. Trump’s assertive approach challenges the traditional separation between the executive branch and the federal law enforcement agency tasked with impartial justice.