The closure of all the investigations that were opened against Israeli policemen following the October 2000 riots comes as no surprise. It would only have been surprising if the police's systemic failure had been translated into indictments against one officer or another.

Essentially, the bloodshed during these riots stemmed from the police's lack of preparedness to cope with nationalist disturbances - events that are somewhere between law enforcement and combat, in which a violent mob endangers besieged policemen and citizens, thereby producing a sense of "the few against the many." Wisdom on the part of senior local officers can make a difference - in Jaffa, for instance, no one was killed - but the one constant was the imbalance in the size of the forces. An isolated, frightened policeman is liable to pull the trigger, while his better-protected colleague will show more restraint.

The Or Commission, like other state commissions of inquiry before it, was simultaneously too weak and too strong. It was too weak because it could only make recommendations, and government agencies can always find creative ways to circumvent recommendations. The Or Commission could order the Justice Ministry's Police Investigations Department (PID) to open investigations, but it was powerless to make these investigations end in indictments. Yet it was also too strong, because it could subpoena witnesses - but their testimonies could not then be used in a criminal proceeding. Thus the suspects were already well rehearsed by the time their criminal investigations began. And without evidence from either the scene of the crime or an autopsy, it is hard to turn question marks into exclamation points.

Israeli suspects, including policemen, have learned from the Sharon family and other senior officials that volunteering explanations is far more dangerous than remaining silent. Silence will work against you during a trial, but it will help to keep you from ever going on trial. Only fools confess. And even if the evidence is solid, a conviction - and therefore an indictment - still requires proof of context and motive.

Every fatal incident during the riots had a limited number of suspects, since the roster of who was stationed where was known. However, that is insufficient to finger a particular policeman as the man who fired a particular fatal shot, and every doubt benefits the suspect. In detective stories, nothing is simpler than matching a body with weapon, motive and opportunity. In real life, O.J. Simpson was acquitted of his ex-wife's murder. Not everything that seems obvious can be proved - and Attorney General Menachem Mazuz and State Prosecutor Eran Shendar have been trying to implement a new policy of indicting only when they are convinced that a court will convict.

The PID both investigates and indicts, in contrast to the usual practice whereby police gather the evidence, but prosecutors decide whether to indict. It is not an elite unit. Transcripts of courtroom testimony reveal that the level of the department's investigations is poor. Its investigators, policemen on loan, are no better than the policemen they investigate. The State Comptroller's Office, in the report it published three weeks ago, was not impressed by the department's performance. Nor did it help the department's reputation when some of its senior investigators were themselves suspected of crimes. In a kind of circular procedure, the police investigated those suspicions. To untie the knot, a new department will have to be established to investigate the PID.