For Nixon, it was a specific audio tape revealing the president's obstruction of justice in the Watergate affair. For Reagan's Iran-Contra scandal, it was an ex-Marine in Nicaragua named Eugene Hasenfus. For Bill Clinton, it was Monica Lewinsky's stained, blue dress.
But for Sheriff Joe Arpaio, his "smoking gun" is a single, double-sided sheet of paper, admitted into evidence during his testimony Friday in his contempt trial before U.S. District Court Judge G. Murray Snow.
The document's front features a timeline of a bogus, anti-Arpaio conspiracy involving the U.S. Department of Justice, the law firm of Covington and Burling, which is partnered with the ACLU in the underlying civil rights case, Melendres v. Arpaio, and the Melendres case itself.
The timeline is dated November 5, 2013, and was faxed directly to Arpaio by the MCSO's confidential informant in the so-called Seattle investigation, Dennis Montgomery, an alleged computer guru and former subcontractor for the CIA and other government agencies.
Arpaio and his Chief Deputy Jerry Sheridan's phone numbers are on the timeline along with fake wiretap numbers. In Arpaio's own handwriting is the notation "CRIM?"
During his brief testimony Thursday, Arpaio said the scrawl referred to a criminal investigation of him and his office by the DOJ, and his suspicion that the wiretap numbers were part of the probe, which was closed September 2012.
On its own, the faxed timeline to Arpaio would be enough of a smoking gun to tie Arpaio directly to the concoction of a conspiracy meant to undermine Snow's court.
But with a memo typed on the back of the fax by Arpaio dated November 6, 2013, the total document is a veritable smoking bazooka.
See, on October 2, 2013, Snow issued a laundry list of reforms for the MCSO, after finding the MCSO guilty of racial profiling in May of that same year.
Later that October, Arpaio met with Cold Case Posse commander Mike Zullo, MCSO detective Brian Mackiewicz, and then-billionaire Tim Blixseth, who told the sheriff, for the first time, about Montgomery.
Montgomery supposedly had the electronic version of a genie's lamp: 50 or so hard drives of data that he claimed to have acquired while working for the CIA and the NSA.
Arpaio maintained throughout his testimony that the focus of the investigation was ID theft, bank fraud and the improper harvesting of U.S. citizen's banking information by the federal government.
According to Arpaio, there were 150,000 victims of this illegal harvesting in Maricopa County, including himself, his wife Ava, and a smattering of local judges, though the only judge he could recall by name was Snow.
This patently obvious cover story, utilized by both Arpaio and Sheridan, is undercut by Arpaio's typed memo to himself, detailing his conspiracy-minded observations.
The memo discusses a phone call Arpaio received from a photographer in San Diego identified by the initials "JC."
JC told the sheriff that Arpaio's and wife Ava's phones were being monitored by "the Feds," so he should change his phone number. The photographer said the information came from a journalist named "Kimberly," who was supposed to get in touch with Arpaio by phone.
The note states Arpaio called JC a week later to find out why Kimberly had not phoned. JC "mentioned the CIA," and said Kimberly had or was going to pick up "sensitive documents," but was afraid to cross state lines for fear of being arrested.
The note says Arpaio planned to send Zullo to San Diego to check out the lead.
Arpaio admitted that he had done so, under questioning by plaintiffs' attorney Stanley Young.
Young asked why the sheriff sent Zullo to San Diego instead of an MCSO detective.
"I believe at the time we were working on the bank situation," said Arpaio. "Zullo knew all the threats I was receiving...I don't think he even located the reporter."
The memo's last paragraph and Arpaio's scrawl at the top are telling.
The paragraph mentions that former U.S. Senator from Arizona Jon Kyl works for Covington and Burling, and that Snow's "wife" works there, though it is actually Snow's brother-in-law who works in the DC branch of the large, international firm. (Note: the issue of the judge's brother-in-law came up many years ago in this litigation, but at the time, Arpaio chose not to make an issue of it.)
The final paragraph goes on to state that Kyl nominated Snow to the federal bench, though in fact Snow was nominated to the bench by President George W. Bush.
Kyl did support Snow's nomination, however.
Arpaio writes that Obama took office in January 2009, not too long after Snow was confirmed by the U.S. Senate. Then, like a mini-J.Edgar Hoover, Arpaio cites Snow's birth date and birthplace, where the jurist went to law school, and Snow's service on the Arizona Court of Appeals.
At the top of the document, in Arpaio's distinctive style, the sheriff writes, "Judge Snow has sister-in-law that works for Covington," though, that, too, is incorrect.
Arpaio also writes, "Wilcox husband in 150,000.00," a reference to Arpaio's longtime political enemy, former Maricopa County Supervisor Mary Rose Wilcox and her husband Earl, who happened to be in the front row of the audience on Friday, observing the proceedings.
Arpaio said this was merely a reference to Earl Wilcox being one of the 150,000 victims of bank fraud.
Asked about the rest of it, Arpaio claimed that he'd just been commenting on the "irony" of the situation, because supposedly Kyl had helped the MCSO become part of the U.S. Immigration and Customs Enforcement's controversial 287(g) program, which allows local law enforcement agencies to enforce federal immigration law.
The Obama administration stripped the MCSO of its 287(g) power in 2009, but Arpaio continued to enforce federal immigration law.
Even when Snow issued a December 2011 injunction ordering the MCSO to stand down, Arpaio persisted. Which is one reason he and Sheridan have admitted to civil contempt of Snow's court, and may face criminal contempt allegations as well.
Young pressed Arpaio on the memo, and why he had made it. Arpaio turned defensive, acting like Humphrey Bogart's paranoid Captain Queeg in The Caine Mutiny, minus the steel ball bearings.
"I have a right to make notes," groused Arpaio, who insisted he was merely "making links."
"Links?" wondered Young.
"Not really links," Arpaio clarified. "It was just [that] in my mind the people [were] connected. Not in a bad way, but it was interesting."
Arpaio then claimed that he'd only recently added some of that information, because he just had seen an article on Kyl joining Covington and Burling "a couple of months ago."
In fact, Kyl joined Covington and Burling in March 2013.
Young, like a psychologist questioning a patient, showed Arpaio portions of the sheriff's recent, videotaped deposition, to refresh the sheriff's memory.
In his September deposition, Arpaio admitted that he had put together all of this info in 2013, under the influence of the fax he'd gotten from Montgomery.
"I was looking at the timeline I got [the day before]," Arpaio said in the deposition video, which was played for the court.
The "links" were because of "the information we got from [Montgomery]," Arpaio added in the deposition.
The smoking gun document was the highlight of Friday's testimony, though Arpaio also made other interesting admissions throughout the day.
The sheriff confirmed that he had set up a meeting with the Arizona Attorney General's Office under Tom Horne to seek immunity for his confidential informant, and that Arpaio attended the first of three such meetings.
Why did Montgomery need immunity? Because of the concern that he might have illegally obtained information from the CIA or the NSA.
Though Montgomery's cache ended up being worthless, this move indicates Arpaio thought at the time the MCSO may have been purchasing stolen, classified documents.
Additionally, Arpaio approved travel by Zullo and Mackiewicz to Washington, DC to meet with a former judge of the U.S. Foreign Intelligence Surveillance Court, Judge Royce Lamberth, about information received from Montgomery.
Attorney Larry Klayman helped set up the meeting with Lamberth, said Arpaio.
The sheriff admitted that some of the information the MCSO was getting from Montgomery was "mind-boggling," but enough of it seemed legitimate to go forward, he said.
Asked about the claims of MCSO employee Lieutenant Kim Seagraves, that he had given $10,000 to Zullo so the former car salesman could work in Seattle, Arpaio was adamant in his denial.
"There's no way I paid [Zullo from] my personal funds," said Arpaio.
However, Arpaio conceded that the MCSO had spent a lot of the public's money financing Zullo's activities, in addition to those of the two MCSO detectives assigned to the Seattle case, and payments of more than $120,000 to Montgomery.
Sheridan pegged the cost of the investigation at $250,000 during his testimony, though a final accounting has not been offered, and sources tell me the total cost is much higher.
The MCSO hired two ex-NSA employees to analyze Montgomery's 50 hard drives of data.
In November 2014, the experts gave the MCSO a report of their conclusions.
"We have found that [Montgomery] is a complete and total fraud," the ex-NSA employees stated in their analysis.
Arpaio said they stopped paying Montgomery, but the MCSO continued to work with the CI well into 2015, pressing Montgomery for a final report, and asking for proof Arpaio was wiretapped.
Montgomery produced neither. Yet, up until April 2015, Arpaio said he was talking to Zullo on a "sporadic basis" about Montgomery.
The first round of hearings in Arpaio's contempt trial began in late April.
Arpaio continued to deny that they had been investigating Snow, but Snow's name was in the mix of the 150,000, the sheriff said. The MCSO had contacted some of the "victims," but it never contacted Snow, and Arpaio couldn't explain why it had not.
The sheriff also admitted that when Snow first asked him about the Seattle investigation in April, he revealed nothing about the 2013 fax to his office from Montgomery.
"I never thought of that timeline when [Snow] asked me the question," said Arpaio. "In retrospect, maybe I should've brought it up."
Arpaio was still on the stand by day's end Friday. He will return to the stand Thursday, October 8. Young may ask him more questions based on the depositions of Zullo and Mackiewicz, which are scheduled for October 7.
No doubt Arpaio will be questioned by his own attorney, the attorneys of other parties, and likely by Judge Snow himself.
Outside the courtroom, Mary Rose Wilcox was asked her what she thought of seeing her husband's name scrawled in Arpaio's handwriting and projected onto a court TV monitor, given Arpaio's history of targeting her, and falsely accusing her of crimes.
"My heart sank when I saw Earl's name," she told New Times. "[Arpaio] has not changed. He is a very vindictive man."