BUENOS AIRES — POLITICAL “suicides” are so common in Argentina that a special word has been invented for them.

Ask different people in Buenos Aires today and they may disagree whether the crusading prosecutor Alberto Nisman was murdered or took his own life. But most everyone will concur that Mr. Nisman was “suicided,” the latest victim of a dark-power centrifuge that with sinister regularity spews out dead bodies in this divided nation.

The historical record does not bode well for clarity in the Nisman case. Juan Duarte, older brother of Argentina’s political saint, Eva Perón, committed “suicide” in 1953, nine months after his sister had thrown the nation into a paroxysm of grief over her own early death, at age 33, from cancer.

Embroiled in corruption scandals and suspected of playing a hand in the smuggling of Nazi funds to Argentina, Mr. Duarte was found, like Mr. Nisman, alone, with a bullet in his head. To this day, historians debate the real cause of Mr. Duarte’s death.