Northern Ireland police announced Thursday they will sue to obtain all of the audiotape interviews of former terrorists who told American researchers about their roles in the bloody civil strife that tore apart the British province for decades. 

The move is designed to reopen scores of cold case murder investigations involving Catholic militants fighting for unification with the Republic of Ireland and Protestant gunmen determined to keep Northern Ireland part of Britain.

Police last year successfully sued Boston College to obtain 11 interviews of Irish Republican Army veterans discussing the 1972 abduction, killing and secret burial of Jean McConville, a 38-year-old Belfast widowed mother of 10.

Those tapes were used as a primary basis for arresting Sinn Fein leader Gerry Adams, who had been accused by some IRA interviewees of being the Belfast IRA commander at the time who ordered McConville's slaying. Adams denied the accusations and was released without charge May 4, although police did send an evidence file to British state prosecutors for potential charges later.

Now, the Police Service of Northern Ireland says it wants the entire audio archive, including the accounts of former Protestant militants of Ulster Volunteer Force involved in the slayings of Catholic civilians. It said Serious Crime Branch detectives have a "statutory duty to investigate fully all matters of serious crime, including murder."

The move threatened more legal trouble for Boston College and the two researchers who collected the oral history, journalist Ed Moloney and IRA veteran Anthony McIntyre.

Dozens of Catholic IRA veterans and Protestant militants agreed to speak to McIntyre starting in 2001 on condition their interviews be kept secret until their deaths. Some of those interviewed have said they plan to sue Boston College to have the tapes and any other records of their interviews returned or destroyed. Boston College itself said it was willing to return the interviews to their subjects. Thursday's police move appears designed to prevent that from happening.