Supreme Court says it failed to identify who leaked draft abortion opinion that overturned Roe v. Wade

The Supreme Court said it has been unable to determine who leaked Justice Samuel Alito's opinion in the Dobbs v. Jackson Women's Health Organization case last May.

After a probe that involved interviews with more than 100 employees, investigators are "unable to identify a person responsible by a preponderance of the evidence," according to the court.

The draft opinion was leaked and published by Politico on May 2. The copy of the draft opinion showed a majority of justices appeared to vote to effectively overturn the 1973 landmark abortion precedent set in Roe v. Wade.

The findings were independently reviewed by former judge and Department of Homeland Security Secretary Michael Chertoff, who provided an independent analysis.

The court does not say the case is fully closed. Marshall Gail Curley, who oversaw the probe, left the door open to the possibility of new evidence emerging down the line.

"In time, continued investigation and analysis may produce additional leads that could identify the source of the disclosure," he wrote. "Whether or not any individual is ever identified as the source of the disclosure, the Court should take action to create and implement better policies to govern the handling of Court-sensitive information and determine the best IT systems for security and collaboration."

On June 24, the court issued its official opinion, which did in fact overturn Roe v. Wade as a national precedent and returned the decision on the legality of abortion to the states.

The leak of the draft opinion immediately triggered protests outside the Supreme Court in Washington, D.C., and across the country. It also led to protesters outside Supreme Court justices' homes in the D.C. area. About a month after the release of the draft opinion, a man was arrested outside Justice Brett Kavanaugh's home with a gun, ammunition, pepper spray and zip ties.

Those protests were triggered again when the official opinion was released the following month.

Both conservative and liberal sides pointed the finger at each other for who was responsible for the leaked opinion. The unprecedented publication of Alito's leaked draft also upended the court's traditional workflow, an iterative process marked by frank and private exchanges of ideas between justices over the course of months.

"What happened at the court is tremendously bad," Justice Clarence Thomas said in June of the leak's impact on court dynamics. "You begin to look over your shoulder. It's kind of an infidelity."

The findings released Thursday did eliminate several options as to what may have occurred in the leak, including saying it is highly "unlikely" the court's IT systems were hacked from outside.

Several other pieces of information about the investigation were detailed, including:

• 82 staff in addition to the justices had access to the draft;
• staff was interviewed under risk of perjury and asked to sign sworn affidavits;
• it is not revealed whether the justices themselves were interviewed;
• several staff admitted to telling a spouse or family member privately the outcome of the case before release; and
• the court received limited outside assistance in the probe, but did do fingerprint analysis of one item of interest.

ABC News' Mark Osborne contributed to this report.