Updated

Northern Ireland police say they have opened a criminal probe into the 1972 Bloody Sunday massacre, when British soldiers shot to death 13 unarmed Irish Catholic protesters.

A police commander, Judith Gillespie, confirmed the move after meeting families of the Bloody Sunday dead Thursday. Nobody has ever been charged over the killings, which inflamed Catholic support for the outlawed Provisional Irish Republican Army.

Gillespie says 15 full-time detectives will collect witness testimony, and then question former soldiers who opened fire as criminal suspects.

When asked how long the investigation would take, Gillespie said she couldn't know but detectives would "go where the evidence takes us."

The Bloody Sunday victims' families and the IRA-linked Sinn Fein party, which represents most of Northern Ireland's Catholic minority, welcomed the move.