A late-night shootout on Tuesday between Border Patrol agents and gunmen in a remote area of Arizona near the border with Mexico left one agent dead and four suspects in custody, and the authorities said they were searching Wednesday for one man who got away. 'The Border Patrol came across five suspects who fired at them, and the agents returned fire,' said Brenda Lee Nath, a spokeswoman with the FBI in Phoenix. 'Unfortunately, one agent was fatally shot.' Killed in the crossfire was Brian A. Terry, 40, who had been an agent since 2007, the authorities said. Terry, a Michigan native, had military and law enforcement training and was in the Border Patrol's tactical unit, said T.J. Bonner, president of the National Border Patrol Council, the agents' union. Bonner said Terry had been attacked by bandits who prey on illegal immigrants crossing the border, robbing and sexually abusing them. Border Patrol and FBI officials declined to comment on the attackers. One of the four suspects under arrest was being treated at University Medical Center in Tucson, officials said. The shootout took place about 11 p.m. Tuesday near Rio Rico, about 10 miles north of the border, and ranchers in the area were told early on Wednesday morning that a fifth suspect, described as potentially dangerous, was on the loose and possibly heading toward the border. There have been 111 Border Patrol agents killed over the years, Bonner said. 'For such a small force to have lost so many agents just punctuates the danger that the men and women face every time they put on their uniform,' he said. 'Even with all their training, sometimes evil gets the upper hand.' The sheriff, Antonio Estrada, said the last Border Patrol agent killed in Santa Cruz County was in 1998. 'That it's dangerous, there's no doubt, but I don't want to overstate it,' Estrada said. 'It's not like we're seeing this happen every day. The border is a lot more secure, but it's not sealed and never will be.' Janet Napolitano, the secretary of homeland security and a former Arizona governor, said prosecuting those responsible would be a priority. 'We will honor his memory by remaining resolute and committed to the serious task of securing our nation's borders,' she said. 