Trump likened the situation with Kavanaugh to the allegations against Saudi Arabia during an interview with The Associated Press.
"You know, here we go again with, you know, 'you’re guilty until proven innocent,'" the president said of claims that Saudis were involved in Khashoggi's disappearance. "I don’t like that. We just went through that with Justice Kavanaugh. And he was innocent all the way."
"We have to find out what happened first," Trump said, adding that both the Saudis and Turkey are investigating what happened to Khashoggi, a prominent dissident Saudi journalist who has been living in the U.S. He has not been seen since he went into the Saudi consulate in Istanbul on Oct. 2 for documents he needed to get married.
Trump made a similar admonition about what he saw as a rush to judgment in Kavanaugh's case, declaring at the justice's ceremonial swearing-in on Oct. 9, that "a man or woman must always be presumed innocent unless, and until, proven guilty."
The president was referring to allegations of sexual assault and misconduct against the nominee that surfaced during the confirmation process, and which Kavanaugh categorically denied.
Trump also spoke about the presumption of innocence a couple of weeks before Kavanaugh's nomination was approved, saying, "Always I heard you are innocent until proven guilty. I have heard this for so long, and it is such a beautiful phrase."
But Trump hasn't always seemed to hold strongly to this legal standard.
From his campaign-rally calls to jail Hillary Clinton or, more recently, Democratic Sen. Dianne Feinstein, to his promoting a controversial police practice of stop-and-frisk, the president has appeared selective in his adherence to the principle of presumption of innocence.
"He is cherry-picking legal standards to benefit a particular political argument that he wants to make, so trying to establish a Trump legal doctrine based on his varying statements about political figures would be quite difficult," said ABC News chief legal analyst Dan Abrams.
"Innocent until proven guilty and proof beyond a reasonable doubt are two criminal law standards, together which recognize the power of the government to take away someone's freedom," Abrams said.
Abrams added that the concepts are standards in criminal law but do not always apply outside of the justice system, such as in decisions by employers and educational institutions.
"We too often throw around the phrase 'innocent until proven guilty' and 'proof beyond reasonable doubt' as if it's un-American to not apply those standards in everyday life, and yet that's simply not the case," Abrams said.
"Lock her up" chants
During the presidential campaign, a common chant at Trump rallies was a call for punishment of the Republican nominee's Democratic rival, former Secretary of State Hillary Clinton.
"Lock her up!" Trump and the crowds would chant.
Those chants have continued at Trump's rallies since he has become president and and at one event recently the crowd extended the call to another female Democrat, Sen. Dianne Feinstein of California.
At a rally in Iowa on Oct. 9, Trump claimed Feinstein's team leaked a letter from Kavanaugh accuser Christine Blasey Ford, to which the audience responded with chants of "lock her up."
Trump laughed and raised his eyebrows when the chants started.
"And I think they're talking about Feinstein," he said.
Feinstein has repeatedly denied leaking Ford's letter, which led to a public hearing where both Ford and Kavanaugh gave testimony about the allegations.
Suggesting James Comey be jailed
Another political target whom Trump has suggested belongs in jail is former FBI Director James Comey.
When Comey started promoting his book in April, Trump went on a Twitter tear that included his suggestion the former FBI chief deserved jail.
"The big questions in Comey's badly reviewed book aren't answered like, how come he gave up Classified Information (jail), why did he lie to Congress (jail), why did the DNC refuse to give Server to the FBI (why didn't they TAKE it), why the phony memos, McCabe's $700,000 & more?" Trump wrote on Twitter on April 15.
Comey responded during an interview on "Good Morning America," saying that such suggestions by a president are "not normal."
"That is not OK. First of all, he's just making stuff up. But, most importantly, the president of the United States is calling for the imprisonment of a private citizen, as he's done for a whole lot of people who criticize him. That is not acceptable in this country," Comey said on "GMA."
The policing tactic of stop-and-frisk involves officers stopping individuals in public and questioning or searching them for weapons or other contraband either in the street or by bringing them into police stations.
The constitutionality of the practice, as well as its effectiveness in crime-fighting, has been questioned for years, and in 2013 a U.S. district court judge ruled that New York City used it in a way that violated the constitutional protection against unreasonable search and seizure.
Some critics also say stop-and-frisk tramples on the principle of presumption of innocence.
The New York Civil Liberties Union in a 2017 analysis said data showed that since 2002, stop-and-frisk was disproportionately practiced in black and Latino communities and that nearly nine out of 10 New Yorkers who had been subjected to the tactic were not found to have committed a crime.
Trump does not appear to accept such criticism or constitutional concerns about the practice.
He called for an expansion of its use when he spoke this month at an International Association of Chiefs of Police convention in Orlando.
In talking about gun violence in Chicago, Trump cited former New York City Mayor Rudy Giuliani's use of the practice. Guiliani is now on the president's legal team and was one of his campaign surrogates.
Trump said at the police convention that he has told Chicago officials "to strongly consider stop-and-frisk. It works, and it was meant for problems like Chicago. It was meant for it. Stop-and-frisk."
"Rudy Giuliani, when he was mayor of New York City, had a very strong program of stop-and-frisk, and it went from an unacceptably dangerous city to one of the safest cities in the country -- and, I think, the safest big city in the country. So it works. It's got to be properly applied, but stop-and-frisk works," Trump said.
The Central Park Five
Another instance of Trump's not appearing to embrace the presumption of innocence standard was in the 1989 Central Park jogger case, in which five male African-American teens were accused of brutally attacking a white woman jogger in New York City.
Trump, then a real estate magnate and New York celebrity, placed full-page ads in the city's four daily newspapers calling for the state to bring back the death penalty, which at the time had been effectively struck down by court rulings.
He didn't directly refer to the suspects in the jogger case but his inference to them was clear.
"Muggers and murderers," the ad reads. "They should be forced to suffer and, when they kill, they should be executed for their crimes."
The five accused made various confessions and served time. But in 2002, they were exonerated after an investigation by the Manhattan District Attorney's Office, The New York Times reported. Another man confessed to the crime and according to the Times, his DNA conclusively linked him to the victim.
Trump didn't change his stance, however.
"They admitted they were guilty," Trump said of the so-called "Central Park Five" in a statement to CNN in October 2016.
"The police doing the original investigation say they were guilty. The fact that that case was settled with so much evidence against them is outrageous. And the woman, so badly injured, will never be the same," he said.