Sinn Fein leader Gerry Adams arrested over 1972 IRA killing

Sinn Fein chief Gerry Adams, the warlord-turned-peacemaker of the Northern Ireland conflict, was being interrogated Thursday over the grisly slaying of a Belfast widow that has haunted his political career for decades.

Adams was arrested on suspicion of ordering the killing of Jean McConville, a mother of 10 in his Catholic west Belfast power base in 1972. That was the deadliest year in four decades of bloodshed, when the outlawed Irish Republican Army was committing killings daily -- and Adams was already a commanding figure.

The IRA branded the 38-year-old woman a British spy but killed her secretly and told her children, who ranged in age from infants to teens, that she had abandoned them.

If Adams, 65, is charged with the murder of McConville -- who disappeared without trace until her bullet-shattered skull was found near a Republic of Ireland beach in 2003 -- it would be a profound surprise and deal a damaging shock to Northern Ireland's precariously balanced peace.