It happened in the middle of a contentious meeting taking place in a country whose political divide seems to grow deeper by the day.
As the room broke for lunch during the confirmation hearings for Supreme Court nominee Judge Brett Kavanaugh, a man approached the judge from behind and was able to get his attention.
Kavanaugh turned to look at the man, who later identified himself on social media as Fred Guttenberg, the father of Jaime Guttenberg, one of the 17 people killed in the Parkland school shooting in February, as he stuck out his right hand. He appeared to say, "My daughter was murdered at Parkland".
Kavanaugh gave the man a look but declined to shake his hand. It is not clear whether he heard Guttenberg's introduction, though the two were standing close to each other. Another man, who a White House spokesman later said was a security guard, had come to Guttenberg's side by that point.
The interaction was captured on camera - both in an arresting photograph shot by AP and multiple video cameras recording from different angles. And it quickly began to circulate on social media, an instant visual artifact trending as a stand-in for a politically complex and emotionally intense moment in American history.
The reactions of those who chose to weigh on in social media seemed to serve as a window into their politics. Some liberals saw Kavanaugh's decision not to shake the man's hand as a contemptuous act, a snub to the family of a victim of a heinous crime, and perhaps, by default, the causes of liberal America, not the least of which remains the issue of gun control.
It is unlikely that those folks would have reacted that way had the man who approached the judge come with a right-leaning grievance, however personal.
"Just walked up to Judge Kavanaugh as morning session ended," Guttenberg tweeted. "Put out my hand to introduce myself as Jaime Guttenberg's dad. He pulled his hand back, turned his back to me and walked away. I guess he did not want to deal with the reality of gun violence."
For some conservatives, it was sign of liberal overreaction and hypocrisy.
To them, Kavanaugh's response was a sign of his confusion at the sight of a man whom security was trying to spirit away.
It is unlikely that many of them, too, would have reacted the same way had it been a man approaching a judge uninvited with a right-leaning political grievance.
In an interview, Guttenberg, who had been introduced at the hearing earlier as a guest of Senator Dianne Feinstein, D, told the Washington Post that he had wanted simply to share his pain with Kavanaugh.
"I wanted to introduce myself, but I also wanted to simply say to him, listen, you have a beautiful family, you're a father," he said.
"I want to know that you are going to look into my eye and understand the pain of a father."
Guttenberg said he is certain that Kavanaugh heard him and disputed that the presence of security had any role in the judge's reaction.
"There was no security intervention," he said.
"When he turned that way and started moving, they started following him. But he had every ability to engage me."
After the lunch break, Guttenberg was questioned by the Capitol Police for about 15 minutes, he said, before they let him return to the hearing.
Deputy White House press secretary Raj Shah tweeted a video of the incident and highlighted the presence of the security worker.
"As Judge Kavanaugh left for his lunch break, an unidentified individual approached him," he wrote. "Before the Judge was able to shake his hand, security had intervened."