Secret Service Scandal Prompts Obama Comment WASHINGTON - President Obama commented for the first time on Sunday about the Secret Service employees accused of soliciting prostitutes before a summit meeting in Cartagena, Colombia, saying he expected a high standard of conduct from his security team and adding that he would be "angry" if the accusations were proved true. "What happened here in Colombia is being investigated by the director of the Secret Service," Mr. Obama said in response to a question at a news conference wrapping up the Summit of the Americas in Cartagena. I expect that investigation to be thorough and to be rigorous. If it turns out that some of the allegations made in the press are confirmed, then of course I'll be angry. He added, "We're representing the people of the United States when we travel out of the country." It was Mr. Obama's first public statement since the Secret Service said Friday that it was investigating suspicions that 11 of its employees had taken part in misconduct in a Cartagena hotel involving prostitutes last week. Those employees were immediately replaced and later put on administrative leave. Five United States military service members who were working with the Secret Service and staying in the same hotel are also facing an investigation because they violated a curfew and may have participated in the misconduct. According to a senior United States official, some of the personnel members sent back to the United States could be interviewed again as early as Monday. The official said he and other senior officials were baffled and angry that two supervisors were involved in the incident and did nothing to prevent it. "It's just extremely poor leadership by them," the official said. Mr. Obama's comments came several hours after Representative Darrell Issa, Republican of California and chairman of the House Oversight and Government Reform Committee, suggested that more Secret Service personnel members may have been involved in the incident. On the CBS program "Face the Nation," Mr. Issa also raised the prospect that the episode had not been isolated and said the Secret Service employees had made themselves susceptible to blackmail. "We think the number might be higher, and we're asking for the exact amount of all the people who were involved," he said. But this kind of breach is a breach in the federal workforce's most elite protective unit, and they don't just protect the president, of course, they protect cabinet members, the vice president, first families, candidates. He added: "Things like this don't happen once if they didn't happen before." Mr. Issa said he had not decided whether to hold a hearing and raised the idea of the Secret Service using lie detectors to prevent similar problems. "We will participate in an over-the-shoulder investigation," he said, adding, "The question is how are they going to make these changes in discipline, and perhaps polygraphs and other items being intensified, so that this can't happen in the future." The head of the Secret Service from 2003 to 2006, W. Ralph Basham Jr., disagreed with Mr. Issa's statement that such incidents were probably more widespread and had occurred before. "Obviously there are incidents that happen, and agents have gotten themselves into compromising situations and disciplined," said Mr. Basham, who is now a principal at Command Consulting Group, a security firm. But it is rare, and this is not the type of thing that is woven through the fabric of the Secret Service. Mr. Basham said he could not recall an incident involving the Secret Service that had received as much attention from the news media. "This is such big story," he said. You don't hear of this happening in an organization like the Secret Service. Avoiding prostitutes is "something people in the intelligence world know about and are taught to be conscious of and told to avoid," Mr. Basham said. As a young agent, you are taught to be careful and aware of your surroundings so you don't get compromised. The agents could have been blackmailed, Mr. Basham said, but the Secret Service mitigated that threat by sending the agents home. Throughout the weekend, the White House has said repeatedly that it still has the highest confidence in the Secret Service. "These men and women perform extraordinary service on a day-to-day basis, protecting me, my family and other U.S. officials," Mr. Obama said on Sunday. They do very hard work under very stressful circumstances and almost invariably do an outstanding job. Jackie Calmes contributed reporting from Cartagena, Colombia, and Eric Schmitt from Washington.