Now Mr. Chertoff has been hired to escort Mr. Samson through the investigative thickets that have grown from the traffic jam scandal. Who will pay the tab? That question has not been answered.

Governor Christie may have promised that he was going to answer questions about the affair, but he, too, has hired a prominent criminal lawyer, Randy Mastro. How much cooperation is in store for the legislative investigation that uncovered the infamous emails?

“The question I’m asked is: ‘Where does your inquiry go if people take the Fifth?’ ” said John Wisniewski, the assemblyman who is chairman of the committee investigating the bridge snarl. “It may or may not have any impact.”

People have the right to remain silent, Assemblyman Wisniewski said, but records do not.

“Most of the information that has led us to the point where we are at now has been through documents,” he said.

So far, Mr. Wisniewski said, three theories have been publicly discussed about why the Christie administration would tie up traffic around the bridge. Two involve retribution. The mayor of Fort Lee did not endorse the governor for re-election. A maneuver by a state senator from that district blocked the appointment of a Christie ally as a judge. The third theory, and most opaque, has to do with a big parcel of land in Fort Lee that, when developed, would use the very lanes onto the bridge that were blocked.

Mr. Wisniewski said the evidence that had emerged so far did not point to any one of the theories with certainty. “There is not a bright line that you could follow from A to B to C,” he said.

“But when you are talking about large sums of money, like the kind that would be involved in those kinds of real estate developments, that sometimes leads people to do dumb things.”