Legal Question in Criminal Law in Washington

It probably means that the case was never 'closed', in the form of a guilty plea, a trial, or other agreement. The 'disposition' field normally would tell you how the case ended. Here, it is likely the person didn't return to court and the warrant issued with the case still pending and unresolved. So when and if the person ever presents themselves back in court, the case will pick up right where it left off.