Authorities working to clear a spa outside Milwaukee, Wisconsin, where three people were fatally shot on Sunday, said what appeared to be an improvised explosive device was hampering the operation. A suspect who has been identified in the killings remained at large, and the incident was being investigated as a possible domestic-related matter, Brookfield police Chief Daniel Tushaus said. Four others were wounded in the shooting, which took place around 11 a.m. at a shopping mall. Bomb squad personnel were at the scene. The suspect was identified as Radcliffe Haughton, 45, of Brown Deer, Wisconsin. President Barack Obama was informed of the shooting in Wisconsin in the early afternoon by Adviser for Homeland Security John Brennan, the White House announced. The President instructed the Federal Bureau of Ivestigation to ensure that state and local officials had the full support of the federal government, the announcement said. \"The President and first lady\'s thoughts and prayers are with the victims of this horrible shooting and their families,\" it said.