Continuity mistake: When the two detectives exit the brownstone belonging to Miller their prime suspect, Miller walks up the sidewalk and starts to run when he sees the police. The detectives and one police officer take off down the stairs twice as they give chase.
Continuity mistake: ADA Price and the defendant's attorney are arguing a motion in the judge's chambers. Price and the other attorney played by Kevin Dunn begin to exit the chambers together but the next scene shows Price coming through the door alone with no sight whatsoever of the Dunn character.
Answer: A courtroom trial that has been terminated prior to its normal conclusion. A mistrial has no legal effect and is considered an invalid or nugatory trial. This often happens when there is a lack of Jurisdiction, an incorrect jury selection or, as seen in many of the episodes, a hung jury, i.e. some jury members finding the defendant guilty while the other members of the jury will find the defendant not guilty and all jury members won't change their decision.