At a hearing in Atlanta federal court on Friday, lawyers for Fulton County put on the witness stand Ryan Macias, an elections expert who advised the county in 2020. He told the judge the federal government's evidence was not "based in reality".
An affidavit an FBI agent used to secure a warrant to search the county's election centre in January "does not make sense" and relies on witnesses "who don't know how elections are conducted," Macias said.
The testimony was part of the county's effort to convince US District Judge JP Boulee that the seizure of more than 600 boxes of 2020 election ballots, approved by a magistrate judge, showed a "callous disregard" for its rights under the US Constitution.
The search of the facility, attended by Director of National Intelligence Tulsi Gabbard, showed how the Trump administration has deployed US law enforcement and intelligence authorities to reinvestigate his loss to Democrat Joe Biden.
Trump has falsely claimed that his defeat in 2020 was marred by large-scale voter fraud and has sowed doubts about the security of US elections ahead of the November midterm elections.
Boulee appeared sceptical of at least some of Fulton County's arguments, questioning whether the county had shown a need to have original copies of the material.
He also noted the FBI included some "contrary information" in the warrant affidavit, including summarising past reports that found no evidence of fraud or intentional wrongdoing.
"How far does the affidavit have to go" in including information that cuts against the FBI's case, Boulee asked, challenging Fulton County's claim the document omitted key facts.
Tysen Duva, the head of the Justice Department's Criminal Division, argued that Fulton County faces a daunting legal bar in showing that the search was improper and had not cleared it.
Duva dismissed Macias' testimony as a disagreement about the evidence and highlighted his lack of involvement in the FBI's probe.
"There is enough in this affidavit to stand," Duva told the judge.
During the search, FBI agents seized a large volume of material related to the 2020 election from the county's election centre in Union City, Georgia, including original 2020 ballots.
Authorities cited alleged "deficiencies or defects" with the 2020 vote, including claims that some digital images of ballots were missing and some absentee ballots did not appear to have been folded as required.
The investigation began with a referral from Kurt Olsen, a lawyer who aided Trump's attempts to overturn the 2020 election and has since been tasked by the White House with re-examining the vote.
Prosecutors cited potential violations of a records retention law and a law that criminalises attempts to deprive or defraud residents of a fair election.
The prospect of more Trump administration probes into the midterm congressional elections this year loomed over the hearing.
Abbe Lowell, a lawyer for Fulton County who is representing several Trump adversaries being investigated by the Trump administration, warned the Justice Department's arguments could allow the federal government to "come into hundreds if not thousands of election centres" around the country.
Fulton County, a Democratic stronghold in a state that has become hotly contested in presidential elections, became the centre of conspiracy theories and fraud claims spread by Trump and his allies following the 2020 election.
Biden's wide margin in Fulton County was key to flipping Georgia in Democrats' favour. The state swung back to Trump in 2024.
