KENOSHA, Wis. >> The judge at Kyle Rittenhouse’s murder trial banned MSNBC from the courthouse today after police said they briefly detained a man who had followed the jury bus and may have tried to photograph jurors.

Judge Bruce Schroeder said the man had claimed to be working for MSNBC. The judge said he was stopped because he was following the bus from about a block behind and went through a red light.

NBC News said in a statement that he was a freelancer who received a citation for a traffic violation that took place near the jury vehicle, and he “never contacted or intended to contact the jurors during deliberations, and never photographed or intended to photograph them.”

The network said it regretted the incident and would fully cooperate with an investigation.

>> RELATED: Kyle Rittenhouse jury resumes deliberating after 2nd mistrial bid

The jurors, who began deliberating on Tuesday, are anonymous by order of the court. Schroeder said they were riding in a bus whose windows had been covered over to keep them from seeing any signs about the case.

Schroeder said the person who followed the jury bus had been told by his boss in New York to do so. Kenosha police tweeted that the person was briefly taken into custody and issued several traffic-related citations.

The judge called it an “extremely serious matter” and said it will be “referred to the proper authorities for further action.”

Rittenhouse, 18, shot and killed two people and wounded a third during a protest against police brutality in Kenosha last year. He testified he fired in self-defense after the men attacked him.

The judge had barred anyone from photographing jurors at the outset of the politically charged trial.