Authorities in Minnesota are continuing to investigate the killings of two police officers and a firefighter who responded to a domestic incident at home in suburban Minneapolis. Investigators say the three were shot by an armed man who opened fire on responders from the home while seven children were inside early Sunday. Another officer was wounded but is recovering at home. The gunman died of a self-inflicted gunshot wound. Because the case is still under investigation, the Minnesota Bureau of Criminal Apprehension hasn’t released more than broad outlines of what transpired and hasn't laid out a timetable for completing its investigation.