" ... if our community, as it must do for good reasons on many occasions, is to detain individuals in custody prior to the determination of their guilt, then that period must be as short as reasonably practicable. Periods of 18 months or so of detention prior to the conduct of trials is by any form of reckoning extremely long. It is not to the point to say, in effect, that such periods represent the norm and, therefore, cannot constitute part of a matrix of exceptional circumstances. This, in effect, ultimately negates the very justification for detention prior to the determination of guilt. What I mean by this is that such detention must be directed to serving the ends of justice and not itself constituting a potential source of injustice."