Fourniret helped locate some of the victims' remains
The trial has opened in France of a man accused of being among the country's worst serial killers in decades.
Michel Fourniret, 65, is charged with murdering seven girls and women in France and Belgium. He is also charged with raping some of them.
His wife, accused of helping lure women into a car, is separately charged with complicity in murder and kidnapping.
Mr Fourniret, dubbed the "Ogre of the Ardennes", is accused of carrying out the murders between 1987 and 2001.
The charges against Mr Fourniret relate to six murders in France and one in Belgium. His alleged victims ranged in age between 12 and 22 years.
Mr Fourniret appeared in court in the northern French town of Charleville-Mezieres alongside his wife, Monique Olivier.
When the judge asked him to identify himself, he held up a piece of paper on which was written: "My lips are sealed if there is no closed-door hearing."
The judge did not appear to respond.
Mr Fourniret also passed to the judge a rolled-up document tied with a red ribbon, which his lawyer said was a message to the victims' families. The judge said he would read it in due course.
Isabelle Laville: Kidnapped in 1987 in Auxerre, central France, aged 17, and raped. Body found in 2000
Fabienne Leroy: Kidnapped and raped in Chalons-en-Champagne, eastern France, in 1988 aged 20. Found next day
Jeanne-Marie Desramault: Kidnapped in Charleville-Mezieres in 1989, aged 22. Body found in 2004 at Fourniret's ex property nearby
Elisabeth Brichet: Abducted in Namur, Belgium, in 1989, aged 12. Found in 2004 at Fourniret's ex-property
Natacha Danais: Kidnapped in 1990 near Nantes, western France, aged 13. Found three days later on nearby beach
Celine Saison: Kidnapped in Charleville-Mezieres in 2000, aged 18, and raped. Body found three months later in Belgium
Mananya Thumphong: Abducted in 2001 in Sedan, north-east France, aged 13, and raped. Found in Belgium in 2002
About 30 relatives of those killed will be present at the trial, which is expected to last two months.
The Frenchman was arrested in Belgium in 2003 after an attempt to kidnap a 13-year-old girl. Now aged 17, she will be giving evidence at the trial, but out of public view.
Mr Fourniret moved to Belgium in the 1980s, after serving a jail sentence for voyeurism and assault.
But he often crossed back into his native France to commit offences, police say.
Police say Mr Fourniret confessed to the murders to Belgian investigators in 2004.
Mr Fourniret's extradition to France followed in early 2006.
He led police to the remains of one of his alleged victims in 2006 - 17-year-old Isabelle Laville, who was raped and murdered in 1987. Her body was dumped in a well.
Two of the bodies were found on a country estate in northern France which he shared with his wife.
Police believe Mr Fourniret may have killed several other women.
Ms Olivier became his wife after getting to know him while working as a volunteer prison visitor.
According to letters seized by investigators, the two agreed a pact while he was in prison. He undertook to kill her first husband if she helped him to kidnap young girls, although he never undertook his side of the bargain.
Investigators say the method used by the couple was nearly always the same.
He would spot a potential victim while driving and stop to ask for directions, then persuade the person to get into his car.
Ms Olivier's presence in the vehicle was designed to help reassure the future victim, according to the prosecution.
She was handed over to the French authorities in 2005 and charged after confessing to having lured women to her home between 1992 and 1997.
Ms Olivier, 59, is alleged to have done so in the knowledge that her husband would kill them.
The cases of two further alleged victims will not feature at this trial and are the subject of a separate legal process.
Mr Fourniret is suspected of kidnapping, raping and murdering British teaching assistant Joanna Parrish, 20, in 1990 while she was working in the French town of Auxerre.
He is also being investigated over the kidnap, murder and attempted rape of Marie-Angele Domece, a 19-year-old disabled woman from France.
He denies involvement in either woman's death.