WASHINGTON — The Justice Department notified three senators on Tuesday that it will not pursue insider trading charges against them after an investigation into stock transactions from the early days of the coronavirus pandemic did not find sufficient evidence they had broken the law, according to a person briefed on the investigations.
The department contacted lawyers for Senators Kelly Loeffler, Republican of Georgia; James M. Inhofe, Republican of Oklahoma; and Dianne Feinstein, Democrat of California. All three had sold substantial amounts of stock in late January or early February when lawmakers were being briefed on the novel coronavirus threat but before the pandemic began roiling financial markets or was fully understood by the public.
Law enforcement officials appear to still be investigating Senator Richard M. Burr, Republican of North Carolina, whose own mid-February stock sales have drawn scrutiny from the Justice Department and Securities and Exchange Commission. This month, F.B.I. agents seized Mr. Burr’s cellphone.
For the other senators, the notifications are likely to begin lifting suspicions that have lingered since mid-March, when they disclosed the trades in mandatory Senate filings. At a time when millions of Americans were losing their jobs and markets had plummeted, even the possibility that members of Congress had used their positions to protect themselves financially prompted cries for resignations and investigations.
A Justice Department spokeswoman declined to comment. An aide to Ms. Loeffler confirmed the notification, and aides for the other senators did not immediately respond to requests for comment.
Though Ms. Loeffler, Ms. Feinstein and Mr. Inhofe had all denied they were personally involved in the investment transactions, much less directing them based on insider information, the F.B.I. had asked them to produce records and other information related to the sales.
Investigators’ decision not to pursue charges would be particularly welcome news for Ms. Loeffler, the only senator of the three up for election this year. Polling suggests that the swirling accusations of misconduct around her multimillion-dollar stock transactions had hurt her standing with Georgia voters at a time when Democrats and a fellow Republican are vying for her seat.
“Today’s clear exoneration by the Department of Justice affirms what Senator Loeffler has said all along — she did nothing wrong,” said Stephen Lawson, a spokesman for her campaign.
The Justice Department typically informs lawmakers when they have closed investigation into their actions but can sometimes take weeks or months to do so, in part to account for the possibility that investigators could find new evidence that would prompt reopening any inquiry, former department employees said.
F.B.I. investigations into Senate or House candidates like Ms. Loeffler require written notification to Justice Department officials, according to a memo issued in February by Attorney General William P. Barr.
Lawmakers can hold and trade stocks. But a 2012 law, the Stop Trading on Congressional Knowledge Act, bars members of Congress and their aides from making investment decisions based on inside information they have access to as part of their Senate work, including both criminal and civil penalties for violations. Legal experts say that determining what information is “nonpublic” can be exceedingly difficult; no one has been successfully prosecuted under the law.
There are also signs that the Senate Ethics Committee may be investigating the sales itself; the bipartisan panel works in secret.
The transactions under scrutiny by the Justice Department and S.E.C. all took place between late January and late February, around when government health and national security officials began warning lawmakers about what would become a full-blown national crisis in March. At that point, Republican senators and President Trump were mostly playing down the threat of the virus to Americans and financial markets were surging.
Ms. Loeffler and her husband, the financial executive Jeffrey C. Sprecher, reported transactions worth millions of dollars beginning in late January, right after senators received their first private briefing from top health officials on Covid-19. The sales included shares of Exxon Mobil, Ross Stores and AutoZone, which later lost value when the markets dropped. And the couple continued to trade in the weeks that followed as the effects of the virus spread.
And Mr. Inhofe sold stock worth as much as $400,000 on Jan. 27, including shares in PayPal, Apple and Brookfield Asset Management, a real estate company.
All three denied any connection between the two events, and they said they left investment decisions to outside financial advisers who had made the trades without their knowledge. In the case of Mr. Inhofe, he did not even attend the January briefing, though as chairman of the Armed Services Committee he is regularly briefed on emerging threats, including pandemics.
As chairman of the Intelligence Committee, he had greater access to government intelligence assessments on how the virus was affecting geopolitics. Unlike the other lawmakers, he has never denied that he arranged his stock sales himself or that he sold the shares out of concern the virus would tank global markets.
Rather, he has said that he made his investment decisions solely on public information, which is legal. And his legal adviser and allies have insisted that he will be proved innocent.
Making a case against him could be difficult, in part because members of Congress have broad speech and debate protections that could prevent investigators from questioning him about what he learned in nonpublic briefings on the virus.
Mr. Burr temporarily stepped down as chairman of the Intelligence Committee this month after the F.B.I. agents took his cellphone and obtained a search warrant for his electronic storage accounts. Because of Mr. Burr’s position, the move had to be approved by the highest levels of the Justice Department, which would mean Mr. Barr, a department official has said.