Then-Sheriff Joe Arpaio with inmates at his controversial Tent City.
When President Donald Trump controversially pardoned former Arizona Sheriff Joe Arpaio in August, he was within his rights - but the pardon didn't allow Arpaio to wipe his crimes from his record. Arpaio was an early Trump supporter and the President said he was treated "unbelievably unfairly".
Bolton handed down her decision roughly one year after she approved a federal contempt charge against Arpaio.
"Why are they going after this Sheriff?" Prosecutors had accused Arpaio of prolonging the patrols for 17 months so that he could promote his immigration enforcement efforts in a bid to boost his successful 2012 re-election campaign.
Trump's pardon raised alarm among civil libertarians, who feared it was a de facto offer of pardon to presidential aides or Cabinet members who may be caught up in the many investigations of Trump. That spared the 85-year-old from up to six months behind bars. His lawyers say the pardon entitles him to the erasure of any record of the conviction.
Quite the contrary, says Bolton.
"The power to pardon is an executive prerogative of mercy, not of judicial recordkeeping", Bolton wrote in the document.
"We will challenge that order", Wilenchik said. "There's no such thing in federal law". "The whole case gets undone", he said.
In July, Arpaio and his department were found guilty of violating a 2011 court order by stopping and detaining drivers based on suspicions about whether they were in the country illegally.
Several legal advocacy groups had requested that the pardon be declared invalid or unconstitutional, arguing that letting it stand would encourage future violations of court orders.