A Police Service of Northern Ireland forensic officer at the scene of the shooting.
LONDON—Northern Irish police on Thursday arrested three men in connection with the shooting of an off-duty detective, in the most high-profile attack on a police officer in the U.K. province for at least a decade.
Detective Chief Inspector John Caldwell was shot by two masked gunmen just before 8 p.m. local time on Wednesday after coaching a children’s soccer team at a sports complex in the western town of Omagh. Senior officers of the Police Service of Northern Ireland said their primary focus is on dissident republican groups, including the New Irish Republican Army, a small paramilitary organization that opposes the peace process that ended decades of bloodshed in the region.