As the jury enters its fourth day of deliberation Tuesday, there is an indication that at least one jury member may be standing in the way of a unanimous verdict, adding an element of uncertainty to the the case of four Boston Teamsters charged with attempted extortion.

The men are accused of using intimidation, threats and violence to pressure the reality show "Top Chef" into hiring union labor.

The defendants, Daniel Redmond, John Fidler, Michael Ross and Robert Cafarelli are each charged with two felony counts: attempted criminal extortion and conspiracy to commit extortion.

The trial featured five days of testimony from prosecution witnesses, who said that Teamsters arrived at a Milton location where an episode of "Top Chef" was being filmed and assailed the crew with vulgar, racist, and homophobic language.

 One witness testified that the tires of vehicles used by the show were later found to be slashed.

Prosecutors argued the men were acting as part of a plot to force "Top Chef" to hire Teamsters that the show did not want or need.

Lawyers for the defendants argued less with the facts of the case, focusing on the motivations of their clients. Resting their case without calling any witnesses, the defense argued that the accused were not extorting "Top Chef". Rather, they were protesting the fact that the show did not hire union labor. Therefore, the lawyers argued, the teamsters conduct was a constitutionally protected exercise of free speech.

As of 3:15 p.m. there are signs that the jury might not be ready to deliver the guilty-on-all-counts verdict prosecutors asked for.

The 12-member jury had been deliberating for some fifteen hours.

On Monday afternoon, the jury foreperson delivered a written question to Judge Douglas Woodlock, who is overseeing the case.

One juror, the foreperson said, was “assuming guilt over innocence.”

"We are not sure how to go on from here,” the note said.

Judge Woodlock issued a hand-written reply reminding the jury that the presumption of innocence over guilt is “not a mere formality” but “of the utmost importance.”

In order to convict or acquit, each charge requires a unanimous verdict by the jury; if jurors cannot reach agreement, the jury will be deadlocked and the judge could declare a mistrial.

The jury could reach different verdicts for each of the four defendants charged.