Law enforcement officials told the senator that they would not pursue charges over his dumping of hundreds of thousands of dollars of stock after Senate coronavirus briefings early in the pandemic.
It was the 13th and final scheduled federal execution under President Trump. President-elect Joseph R. Biden Jr. has said he opposes the death penalty.
A division of the Immigrations and Customs Enforcement agency, working with the Justice Department, is hunting down websites offering fraudulent deals to buy coronavirus vaccines.
States carried out fewer executions in 2020 than in any year since 1983, but the federal government carried out more than it had in over a century.
The Houston-area men charged a foreign government more than $317 million for the masks, about five times the public list price, the authorities said.