The killing marks one of the lowest points in the bitter relationship between the Israelis and the Lebanese Shiites and their Iranian sponsors.

This killing marked the beginning of a series of attacks on businessmen.

But Osama bin Laden's killing may mark the point where the water boiled over - destroying Pakistan's relationship with the West, and setting off a chain of events no one can predict.

The killing marked a low point in the record murder year of 1990 and led to an increased police presence in New York.

If only the killing of Muhammad al-Durrah marked the beginning of forgiveness and the end of killing, particularly of children.

The boundary between allowing to die and active medical killing marks a moral Rubicon.

The killings of 28 February marked the start of a ten day Civil War and the beginning of anarchy in southern Albania for about a year.

The killing of Eileen Turner marks the beginning of a new killing spree by Red John.

For the Italian authorities, the killing of Judge Falcone also marked a turning point.

The killing of one of the bikers marks a serious escalation in the violence between the city's two motorbike gangs.