Six suspects have been arrested, including a former government minister, Alain Van der Biest, who was a Socialist Party associate of Mr. Cools and a fellow Freemason. The police also recovered the murder weapon from a canal after one of the suspects told them where to look.

It was the latest twist in a complex chain of events mingling crime and political corruption.

Random murders in supermarket parking lots in the late 1980s, widely seen as an attempt to destabilize the state, still have no explanation. Financial scandals have become commonplace. A storm over kickbacks on defense contracts involved the suicide of a general and the resignation of the NATO secretary-general. More recently, there has been a string of attacks on armored cash trucks by criminals armed with bazookas and battering rams.

Belgium's forces of law and order have sunk in public esteem since it is clear that had they been better organized and coordinated they would have caught on to the activities of Mr. Dutroux much earlier than they did and perhaps, the parents say, have saved the lives of their children.

Belgians commonly believe that Mr. Dutroux had powerful protectors. How else, they ask, was he able to be released in the early stages of a 13 1/2-year sentence for the savage rape of a half-dozen young girls, despite appeals by his mother and sister to keep him in jail.

"Something stinks in this release," Jean-Pierre Dewaele, a retired prison psychiatrist, told the magazine Humo. "Either there was an accumulation of mistakes and the system failed in every respect or there must have been bizarre interference."

The minister of the interior at the time, who signed the forms for Mr. Dutroux's parole, Melchior Wathelet, now a judge in the European Court of Justice, was notoriously stingy with parole requests. Yet, there is no indication that the police or social services investigated Mr. Dutroux's background before his release. No one questioned why, despite being fresh out of prison, unemployed and receiving welfare benefits, he was able to tender 2.5 million Belgian francs (about $80,000) for a house and plot of land.

Mr. Marchal said to extended applause during his daughter's funeral that she might not have died had the energetic judge in the Dutroux case, Jean-Marc Connerotte, been allowed to start his investigation earlier.