Washington, D.C.’s federal appellate court on Thursday declined to rehear a major case on the rights of street demonstrators, sparking a worried dissent from one judge that the decision could have a chilling effect on political expression.

In its order, the U.S. Court of Appeals for the D.C. Circuit let stand a ruling from November (pdf), in which a three-judge panel found that police had the right to arrest an entire group of marchers once some members of the crowd began to riot, even if officers never ordered the crowd to disperse. The case grew out of a protest in Washington’s Adams Morgan neighborhood on the eve of President George W. Bush’s second inauguration. A number of protesters were arrested in an alley away from the main demonstration, which had turned violent, and they later sued claiming constitutional violations.