Attorney General Merrick Garland announced his appointment of U.S. Attorney David Weiss of Delaware as special counsel in the ongoing investigation into Hunter Biden, President Biden’s son. This was the right move. It should encourage Americans that the process will be independent and transparent and, therefore, that it is more likely to be fair.

Such assurances might not have been necessary at the beginning of the Justice Department’s Hunter Biden probe, but they became important after a plea agreement between Mr. Weiss and Mr. Biden’s attorneys fell apart under judicial scrutiny. Initially appearing reasonable, the deal turned out to include peculiar details suggesting critics might have been justified to suspect that Mr. Biden was being given special treatment.

For example, the plea deal would have required the presiding judge to decide whether Mr. Biden was complying with the terms of a diversion agreement that would have allowed him to avoid some formal charges. Diversion agreements aren’t unusual for nonviolent first-time offenders with substance-abuse problems. But asking a member of the judiciary to help enforce one of them may be unprecedented, and the judge expressed concern that the agreement could be ruled unenforceable down the road.

Also, strangely, Mr. Biden’s attorneys and prosecutors appeared to have differing views about whether the president’s son could face further charges under the deal, spurring questions about whether the two sides came to any private understandings not spelled out in the written agreement.

Meanwhile, two IRS whistleblowers claim they weren’t allowed to pursue their investigation into Mr. Biden because of political sensitivities, another reason Mr. Weiss may have asked Mr. Garland to grant him the formal independence that comes with being a special counsel.

Special counsels should not be appointed lightly. They have tended to overspend and overreach. One temptation in the Hunter Biden case might be to investigate the president himself, as many of his critics wish. So far, the record suggests President Biden’s behavior was not spotless — but also not criminal.

Nevertheless, Mr. Garland’s move was justified. Under the special counsel regulations, Mr. Weiss will not only be clearly authorized but also required to produce a report, almost certain to be made public, on his investigation. The report will allow Mr. Weiss to explain the prosecutorial choices he has and will make. The fact that he has to write one will also give him a greater incentive to proceed by the book.

The imperative in this case remains what it has always been: to treat Hunter Biden, as far as possible, like any other defendant. Mr. Weiss has all the independence and resources he needs.

This editorial first appeared in The Washington Post on August 12, 2023. It was distributed by The Associated Press.