Reliable Sources host Brian Stelter took apart Trump and his allies in right wing media for their ridiculous assertion that the FBI was so busy investigating Russian interference in the 2016 presidential election that they didn't have time to do their job looking into the Parkland Florida shooter.

Stelter also sounded the alarm on Trump's increasingly unhinged Tweets, the latest of which took place just a few hours before his show aired.

Transcript via Media Matters:

BRIAN STELTER (HOST): Unfortunately, two stories have merged this weekend. The pain that we all feel after the latest mass shooting, and the confusion we all feel about the Russia probes. These stories have come together. While these grieving students in Parkland, Florida are asking politicians to protect them and announcing a march on Washington, the president of the United States is making it about himself.

[...]

It's clear the president is feeling the heat of Robert Mueller's special counsel, and he's lashing out, implying that the FBI might have failed to stop the shooting because it's too obsessed with Russia. Let's be clear: The president is insulting your intelligence. Let's pull up FBI.gov, it says right there, "the FBI employs 35,000 people."

There are a small number of FBI agents working on the Mueller probe, but they have nothing to do with the investigation of tips like the one that was missed before the Parkland shooting.

[...]

Aha. So that's where President Trump got the idea. Yes, this has been a talking point from pro-Trump media ever since Friday, that there's a link between the FBI's failure and the ongoing Russia probes. Again, this is nonsensical, but I want you to see what's going on behind the scenes. Geraldo [Rivera] said that on TV on Saturday morning, and then on Saturday evening what did Geraldo do? Ah, he was in Mar-a-Lago, he had dinner with President Trump. That's according to new reporting from The Washington Post. Now, when did Trump tweet that nonsensical claim? 11:00 p.m. Saturday. You tell me if there's a connection there.

But the tweets have continued all weekend long. Here are just some of the tweets from the president. You look at what he is doing here, he's undercutting his own national security adviser. He is ranting and raving about the "fake media." He's got tweets riddled with misspellings and profanity. I don't know, maybe down at Mar-a-Lago, maybe in person President Trump is cool, calm and collected. But on Twitter, he sounds deeply troubled. He sounds unhinged. This is why questions about his fitness for office are so urgent. This is the biggest story that I see happening right now