It was meant to be a dramatic confrontation, a public accusation of perjury against Jack Smith, the special counsel who investigated Donald J. Trump. Instead, Senator Eric Schmitt’s amateur sleuthing into basketball led him to the wrong game, league and state. During a four-hour Senate Judiciary Committee hearing, Mr. Schmitt, a Republican from Missouri, struck a conspiratorial tone and asked Mr. Smith if he had attended an Atlanta Hawks home game in February 2024.

Mr. Schmitt focused on the basketball game in the hopes that he could show Mr. Smith had perjured himself and was involved in a conspiracy with local Atlanta prosecutors to ensnare Mr. Trump. In a hearing where Republicans repeatedly accused Mr. Smith of lying, what Mr. Schmitt first presented as smoking-gun evidence against Mr. Smith turned out to be a misfire. During his testimony, Mr. Smith appeared deeply confused and said, “I definitely did not go to a Hawks game. I’m sure of that.”

When the former special counsel insisted he had not gone to see the Hawks, Mr. Schmitt declared, “I think you’ve already perjured yourself,” and called Mr. Smith a “dirtbag.” The accusation appeared to unravel almost immediately. Invited to respond by Senator Amy Klobuchar, Mr. Smith said he had, in fact, attended a basketball game on that day, but it was to see the Iowa Hawkeyes at the University of Maryland. Ms. Klobuchar suggested that Mr. Schmitt’s accusation was rooted in confusion between the “Hawks” of Atlanta and the “Hawkeyes” of Iowa. Mr. Schmitt declared that he still stood by calling Mr. Smith a “dirtbag,” then left the hearing.