It seems like the writers decided to try something different this year, with a couple of epsiodes deviating from the usual formula.
This episode kicks off in the middle of a court hearing, where Warrick is giving evidence for the prosecution. All seems to be going well, until it is discovered that the search of the defendants vehicle was performed without a warrant, and the CSIs are left with 24 hours to come up with new evidence or the accused walks free. Within 24 hours, the CSIs are led to believe that the accused is not actually the killer, and indeed find evidence to that effect. The real killer is taken into custody, and in the end we see another court hearing taking place where Warrick is providing his evidence, and the Judge decides to take the case to trial.
An excellent episode of CSI.