The president's tweet was short: "FAKE NEWS," he wrote on Thursday. "THE ENEMY OF THE PEOPLE!"
Joshua McKerrow's response was long.
"Today I did the annual story on holiday decorations at the Governor's residence," the Maryland photojournalist wrote, starting off on a seemingly cheery note. "I've done it every year, for years. A very light but very fun story."
In years past, McKerrow said, he worked with reporter Wendi Winters. This year, he was paired with Selene San Felice.
"Wendi was murdered in June," McKerrow wrote.
McKerrow works for Capital Gazette — the small paper in Annapolis, Md., that was attacked by a gunman this summer. Five of his colleagues were killed in the shooting, which authorities described as a "targeted attack."
In his tweets, McKerrow explained how it felt to cover the holiday decoration story without Wendi Winters by his side. "I could almost hear her voice echoing through the empty rooms. 'How many cookies are you making this year?', her favorite question," he wrote.
"I was ok til the very end. Interviewed the butler, like I have every year, and when we were done she took me aside and whispered, 'I really miss Wendi. Next year I'm going to name a cookie for her.' ... And that was it. The tears started, and I'm standing in the Maryland Governors home weeping to myself about my dead friend. She died in The Capital newsroom on June 28th, shot by a man who wanted to kill every journalist he could."
"Wendi was no one's enemy," McKerrow said.
"I don't have a wrap-up to this story," he said. "I cried on and off all day. I miss her very much. ...We'll keep on doing the work. And if we die for it, someone else will pick up the threads, and report on the holiday decorations at the Governor's house. Its what we do."
Tens of thousands of people have liked the thread.
Increasingly, journalists have been pushing back on the slur. In August, hundreds of newspapers published coordinated op-eds to denounce the president's repeated attacks on the press.
McKerrow was one of several Capital Gazette journalists who kept working in the immediate aftermath of the shooting, covering their own colleagues' deaths. He tells NPR he was out of the office when the shooting began.
"I got a phone call from my editor. He had heard a rumor of what had happened and was trying to track people down," he said. "I was traveling on the highway. At about the same instant that I was talking to him on the phone, I saw a fleet of emergency vehicles heading the opposite direction towards Annapolis. And as soon as I saw that, my heart sank. I just knew that something terrible had happened."
McKerrow turned around, posted on social media to say he was safe and on his way, and drove back to the office. He immediately began taking photos, which ran on the website and then in the next day's paper — editing and writing from a pickup truck in a nearby parking garage.
"There was no decision made," he said. "It was, of course we were going to put out a newspaper. I don't think the question even came up that we weren't."
His colleagues who were killed, he says, were community newspaper journalists.
"They're not journalists who want their names in big letters," he said. "They were the journalists, the engines that make community papers run, that make American journalism run."
"They would not have wanted to be a story," he says. "They would have wanted to cover the story."