In a span of four days, a controversial former police chief’s theory linking the FBI’s Russia investigation and the Florida school shooting made its way to the president of the United States’ Twitter account, where he shared it with his 48 million followers.

Of course, it’s not the first time Trump has tweeted something controversial. But the fact that the president used a national tragedy to disparage the credibility of special counsel Robert Mueller’s investigation into whether the Trump campaign colluded with Russia is raising some eyebrows.

On February 17, the president tweeted:

Very sad that the FBI missed all of the many signals sent out by the Florida school shooter. This is not acceptable. They are spending too much time trying to prove Russian collusion with the Trump campaign - there is no collusion. Get back to the basics and make us all proud! — Donald J. Trump (@realDonaldTrump) February 18, 2018

This idea originated with Bernard B. Kerik, a former NYC police commissioner, who tweeted his theory on February 15 — two days earlier, and less than 24 hours after the school shooting that left 17 people dead.

Kerik — who was sentenced to four years in prison in 2010 for tax fraud and lying to White House officials — said the Bureau was “wasting resources” on the Russia investigation, and implied that this was why the agency had failed to stop the attack.

The @FBI knew about Cruz, they knew about the bomber in NJ/NY, they knew about the husband and wife in San Bernardino, and they knew about the Boston bombers, yet we're wasting resources chasing Russian collusion and harassing @GenFlynn. Time for @jeffsessions to do something! https://t.co/2XhKkLzvNP — Bernard B. Kerik (@BernardKerik) February 15, 2018

Kerik’s tweet was picked up by RT, the Russian government-funded news agency, in a matter of hours. They included the tweet in an article that outlined how the FBI mishandled previous tips about the potential danger of the Parkland shooter, citing a BuzzFeed article published early Thursday morning.

Breitbart, the far-right news site formerly headed by once-White House strategist Steve Bannon, ran with the story on Friday morning. Their headline read:

Four days later, the president tweeted out a very similar version of Kerik’s theory, accusing the FBI of being distracted by the Russia scandal and doing a poor job.

After the president’s tweet, the idea continued to cycle through conservative media and was referenced on Sunday’s episode of Fox New’s popular morning show Fox & Friends.

"You have the leadership of the FBI distracted, trying to go follow this trail of Russia collusion which, by the way, the indictment now says no Russia collusion," co-host Rachel Campos-Duffy said. "This is why the president’s frustrated. We’ve wasted a year on this."

There’s absolutely no evidence or basis for the theory that Kerik put forth and that Trump tweeted, and Trump has been criticized for attempting to distract from special counsel Mueller’s ongoing Russia investigation.

On Friday, Mueller issued indictments for 13 Russians and three Russian companies for using propaganda tactics over social media to influence US voters in the 2016 presidential election.

Trump responded over the weekend with a tweetstorm, saying that these indictments prove there was no collusion between the Trump campaign and Russia.

Russia aside, the FBI acknowledged that they failed to follow protocol

Early Thursday morning, BuzzFeed reported that the FBI was tipped off about the violent intentions of accused shooter Nikolas Cruz and the information was not passed along according to the FBI's protocol.

The FBI released a statement on Friday saying they received a warning from someone close to Cruz who had talked about “Cruz’s gun ownership, desire to kill people, erratic behavior, and disturbing social media posts.”

In the statement, the Bureau admitted that Cruz should have been "assessed as a potential threat to life." The tip was also not referred to the FBI Miami field office, which could have started an investigation.

FBI Director Christopher Wray, who was quoted in the statement, expressed his condolences to the victims and said they would do better. “When members of the public contact us with concerns, we must act properly and quickly,” Wray said.

The shooting took place Wednesday at Marjory Stoneman Douglas High School in Parkland, Florida. Cruz was arrested shortly after the shooting and will reportedly plead guilty to 17 counts of premeditated murder.