PITTSBURGH — Throughout the painstaking selection of jurors in the Bill Cosby sex assault trial, a stern, gray-haired man has sat in the prime position between the famed entertainer and his two high-powered lead attorneys.

The man’s name has never been announced, but his central role in the saga has been clear. The attorneys seek his input on almost every major decision. Previously undisclosed court records reveal that the man is David Weinberg, the founder of a Minnesota-based jury consulting firm called JuryScope. He’s assisted by three associates, one of whom is Carrie Mason, an adviser who worked on the case of Scott Peterson, a California man convicted of killing his pregnant wife, Laci, in a case that became a tabloid sensation.

Jury consultants can be critical. One of the most famous jury consultants in the country, Jo-Ellan Dimitrius, gained widespread attention for helping select the jury that acquitted football star O.J. Simpson of murdering his wife, Nicole Brown Simpson.

The selection of Weinberg and Mason — along with their associates Amy Ziegler and Emily Ryan — appears on the surface to be something of an unconventional choice. Much of the work their firm touts on its website is focused on corporate legal cases. The jury consultants could not be reached for comment.

Weinberg’s bio, which lists only the cases he’s been authorized to discuss, ticks off cases involving disputes over patents, licensing and insurance. He also worked on an antitrust dispute involving American Airlines, and a white-collar case involving William Ruehle, a former Broadcom executive, accused in an options scandal.

Ryan’s bio says she has “spent much of her professional career working as a lobbyist at all levels of government, representing a variety of public and private sector clients” and adds that she has frequently appeared as a commentator on Phoenix television stations. Ziegler’s bio says she “specializes in gathering and analyzing demographic and census information.”

Court officials have struggled to seat a full jury. The defense has accused prosecutors of systematically excluding African Americans, an argument rejected by the judge, Steven T. O’Neill. Eleven jurors — 10 white and one black — have been seated so far. Selection is scheduled to resume Wednesday with a second group of 100 potential jurors.

The task of picking the final juror and six alternates got even tougher Wednesday when a second jury pool was assembled following two days of questioning of the first pool. Half of the second pool said they’d already formed an opinion of Cosby’s guilt or innocence. That’s a larger number than the first pool in which one-third had formed an opinion.

Cosby trial coverage: