Investigators say they are looking for a former employee in Tuesday's fatal shooting at Dollar Tree in Brockton. The shooting happened just before 2 p.m. at the Dollar Tree at 999 North Montello St., police said.Police said a man walked in with a firearm and fired some shots, and two men were injured. Both men were taken to Good Samaritan Hospital for treatment, where one man died as a result of his injuries. He was identified as Dongbin Pyon, 38, of East Boston.Investigators sought and obtained an arrest warrant for 32-year-old Luis Soto, a former employee of the Dollar Tree store. "Preliminarily, this does not appear to be a random act of violence," District Attorney Tim Cruz's office said in a statement.After the shooting, Soto fled the store scene and remains at large, investigators said. "We are aware of the tragic incident at our store in Brockton ... and are actively assisting law enforcement with their investigation," a Dollar Tree spokeswoman said in a written statement. "Our hearts go out to the victims of this horrible crime."Soto should be considered armed and dangerous, and anyone with information on Soto or the shooting is asked to contact Massachusetts State Police or Brockton police.