He evaded arrest, despite being spotted several times and smashing his way through a roadblock between Nimes and Montpellier.
Albert Foulcher, a 50-year-old former insurance salesman, went on the rampage in Narbonne on Monday, killing two policemen and two men who testified in a murder trial against him.
He evaded arrest, despite being spotted several times and smashing his way through a roadblock between Nimes and Montpellier.
More than 400 police officers are manning roadblocks over a 100km area and using helicopters to survey the surrounding countryside.
Chase
In 1993, Mr Foulcher was jailed while a judicial investigation into the murder of a business associate was being conducted. He was released three years later after his case failed to come to trial.
After disappearing in 1998, he was tried and convicted in absentia, prompting officials to order an international warrant for his arrest.
On Monday, Mr Foulcher killed former colleague Pascal Herrero, who had given evidence against him at the trial.
He then shot dead two police officers who arrived at the scene, before fleeing in a stolen car.
Driving to an area 10km northeast of Narbonne, he killed Maurice Michaud, a former business associate who also testified at the trial.
Mr Foulcher left the scene in Mr Michaud's car, sparking a police chase that lasted through the night.
"We are seeing him a little bit everywhere, unfortunately," said one police officer, who said Mr Foulcher had changed direction several times.
Police have now provided bodyguards for two more people connected with the murder trial.