NEW YORK » On Tuesday night, after President Barack Obama completed his State of the Union speech, a highly unorthodox scene unfolded for anyone tuned into NY1, the cable news channel for New York City.

It began innocuously. Rep. Michael G. Grimm — the only New York City congressman who is a Republican — ventured over to the interview area of NY1’s Washington reporter, Michael Scotto, in the Capitol rotunda. After Grimm, 43, delivered what Scotto found to be a predictable reaction, Scotto tried to pose a question about an ongoing federal investigation into Grimm’s fundraising.

Irritated, Grimm stormed off. He then returned and threatened to toss Scotto over the balcony, employing an obscene adjective to characterize the balcony. During the exchange, the congressman, standing close to Scotto, spoke in a barely audible whisper, facing away from the camera.

At one point, he said that Scotto was "not man enough" and suggested: "I’ll break you in half. Like a boy."

The snappish exchange quickly became the topic of choice in political circles and on social media, as video of the showdown whipped around the Internet.

The burst of attention on Grimm, a two-term congressman, a former Marine and a former FBI undercover agent, prompted revelations of other situations involving him that showed a hair-trigger temper.

Bob Hardt, NY1’s political director, said in a statement that the "bizarre and scary rant" was indicative of Grimm’s behavior whenever the station raised the campaign-finance probe. In December 2012, he said, Grimm "blew his top" off camera after Errol Louis, a political anchor, asked about it. Hardt said Grimm shouted at both Hardt and Louis and insinuated that they resolve things by "taking it outside."

Grimm’s initial response to Tuesday’s incident was a huffy, unapologetic statement. Later Wednesday morning, he called Scotto and apologized. Scotto, 35, described it as a short conversation during which Grimm said he had overreacted.

"He said the behavior he showed last night was ‘not me,’" Scotto said. "I accepted his apology. He said he wanted to bury the hatchet over lunch."

Scotto said the apology seemed sincere "but it’s always hard to gauge these things in a phone conversation."

Speaking later with reporters at the Capitol, a more congenial Grimm explained that he had had "a long day fighting for flood insurance" for his constituents and "I lost my cool." Asked if he had been drinking, he laughed it off as "silly."

Had Scotto made the same threat against Grimm, Scotto could have been charged with a federal crime.

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