A grainy video became a focal point on the final day of testimony Thursday in the so-called mailbox case.

But it was not that video — the fuzzy one showing a man pulling a Kahala mailbox from its pedestal one night in June 2013.

This one showed an attorney on the witness stand during a break in his testimony Tuesday in the public corruption trial of retired Police Chief Louis Kealoha and his wife, former Deputy Prosecutor Katherine Kea­loha, and three current and former Honolulu police officers.

Prosecutors on Thursday submitted the courtroom security video as evidence to undermine attorney Kevin Sumida’s prior testimony as a defense witness for Katherine Kealoha.

The courtroom video was part of the government’s effort to rebut defense testimony. Prosecutors called only three rebuttal witnesses Thursday, the last of nearly 80 people who took the stand over 16 days at a trial that started May 22.

After the three witnesses testified, jurors were dismissed until Tuesday morning.

That’s when U.S. District Chief Judge J. Michael Seabright is scheduled to give instructions to the jury, followed by attorneys for the prosecution and defense presenting their closing arguments.

After that the fate of the five defendants will be in the hands of the seven men and five women who have sat through the 16 days of testimony and viewed reams of evidence.

Before jurors were brought into the courtroom Thursday, the two sides argued over the relevance of presenting evidence about Sumida’s actions during a break in his Tuesday testimony.

Michael Wheat, lead prosecutor for the federal government, said courtroom security footage would show Sumida on the witness stand going through documents that were left there when the court recessed in the middle of his testimony.

After the proceedings resumed, Wheat asked Sumida whether he had been reviewing documents during the break.

“Were you looking through those documents?” the assistant U.S. attorney asked.

“No, not at all,” Sumida answered.

Yet the footage showed otherwise, though the quality of the video — especially when magnified — was noted by Seabright before the jury was brought into the courtroom.

“The video is, I hate to say it, a little grainy,” the judge remarked, sparking laughter throughout the courtroom.

The grainy mailbox video is a key piece of evidence in the case.

Earle Partington, one of Katherine Kealoha’s attorneys, said Sumida’s actions during the Tuesday break were done in open court and with prosecutors nearby.

“I don’t understand what the concern is,” Partington said as the two sides argued without the jury present.

But Wheat said Sumida three times vehemently denied going through the documents and that those denials undermined the veracity of his testimony. “It goes to his credibility as a witness,” he said.

Seabright allowed prosecutors to raise the issue.

Once the jury was seated, Wheat played two courtroom videos for jurors: a version that was not magnified and another that zeroed in on Sumida. The quality of neither was high, but in both the man at the witness stand can be seen flipping through documents off and on for about two minutes.

Charles Goodwin, the U.S. marshal for Hawaii, was called to the stand Thursday to answer questions about what he saw Sumida doing during the break Tuesday — Goodwin was standing at the back of the courtroom — and to verify the security video’s authenticity. Security officers at the court oversee the video system and report to Goodwin.

Questioned by Partington, Goodwin acknowledged that Sumida did not appear to be hiding his actions.

Goodwin also said Sumida was quickly going through documents but stopped occasionally for a longer look.

Sumida represented Katherine Kealoha in a 2013 lawsuit in which she was sued by Gerard Puana, her uncle, and Florence Puana, Gerard’s mother and Kealoha’s grandmother. They alleged that Kealoha stole hundreds of thousands of dollars from them. But the jury sided with Kealoha in the case. The decision is on appeal.

The five defendants, including Lt. Derek Wayne Hahn, officer Minh-Hung “Bobby” Nguyen and retired Maj. Gordon Shiraishi, are charged with conspiring to frame Gerard Puana for the alleged theft of the Kealohas’ Kahala mailbox and lying about their actions to federal authorities.

Prosecutors say the defendants tried to frame Puana in an effort to discredit him.

The grainy video at the heart of the federal case shows a man in a hat taking the Kealohas’ mailbox from its pedestal the night of June 21, 2013.

About a week later Katherine Kealoha told police the man in the video was Puana.

But prosecutors say that wasn’t him, though they never have said who they believe it is.