ARIS, Nov. 5 — In a surprising twist to a euthanasia case that has captivated the nation, the head doctor of the intensive care ward where a French paraplegic, Vincent Humbert, died six weeks ago is expected to be charged with premeditated murder for injecting Mr. Humbert with poison.
The death of Mr. Humbert, 22, which was initially ascribed to his mother, Marie, came after an unsuccessful nine-month campaign by his supporters to make euthanasia legal, an effort that set off a national debate over the issue of assisted suicide.
Any charges in the case are likely to intensify that debate, which has divided the cabinet of Prime Minister Jean-Pierre Raffarin, who opposes modifying the laws that make euthanasia a crime in France.
Justice Minister Dominique Perben told French radio on Wednesday that it was probably "not possible" to maintain the status quo on the emotionally charged issue.
In interviews with news organizations before the third anniversary of the car accident that left her son paralyzed, mute and blind, Ms. Humbert hinted that she would fulfill her son's wish to die.
He died two days after that anniversary, and a day after the publication of a book, "I Ask the Right to Die," that he had dictated by signaling each letter with movements of his head and thumb.
Initial news reports indicated that Ms. Humbert had injected her son with barbiturates and that he died after doctors decided two days later to remove him from life support machines. The head of the intensive care unit, Dr. Frédéric Chaussoy, later asserted that he had personally caused the death by disconnecting Mr. Humbert's respirator.
But the state prosecutor's office in the northern French port of Boulogne-sur-Mer, where Mr. Humbert died, issued a statement on Wednesday saying that an investigation begun a month after the incident had found that the death "was not the direct result of stopping the artificial respirator but of the administration of Nesdonal and potassium chloride in two successive injections by the doctor."
Nesdonal is a barbiturate. Potassium chloride, commonly used in lethal injections for executions, induces cardiac arrest.
The statement said the prosecutor had asked that Dr. Chaussoy be charged with "premeditated poisoning," a crime that carries a possible life sentence in prison. It said Ms. Humbert might be charged with "premeditated administration of toxic substances to a vulnerable person," a crime carrying a maximum prison sentence of five years.
The prosecutor's office said it expected the charges to be filed within a few days.
A lawyer for Ms. Humbert, Hugues Vigier, told French radio on Wednesday that Dr. Chaussoy had administered the barbiturate and poison to prevent any suffering caused by disconnecting the respirator.
Dr. Chaussoy's lawyer, Antoine Duport, told Agence France-Presse that she and her client hoped that the presiding judge would dismiss any charges because of the exceptional nature of the case.
