Police in Saint Louis, Missouri were searching for a gunman who killed three people and wounded five others in a morning rampage at the offices of a Swiss power company. Police confirmed the deaths in the shooting spree that began at the start of the morning shift when a man armed with an assault rifle and a handgun entered the offices. Police Captain Sam Dodson could not confirm local television reports that the shooter, named by police as Timothy Hendron, was among the dead. Five other people were wounded, three of whom were in critical condition, a city spokeswoman said. Dodson said there was no indication there was more than one shooter, and he confirmed Hendron was believed to be a former employee of the power company. According to court documents, Hendron was involved in a legal dispute with the company over the management of employees" retirement funds. Police special forces entered the offices of ABB Power after reports of the shooting at the busy factory of 270 workers. "There is a large business at this location with numerous employees inside of the building," a police spokeswoman said. "The shooter is thought to be at this location, but he is currently unaccounted for." "We believe [the suspect is] in the complex right now. That"s why our tactical [teams] are going room by room. It"s a very large complex, very compartmentalized," Dodson said. "It"s a very slow and methodical process, and it will take several hours."