After the Secret Service scandal erupted nearly two weeks ago, the accusations of egregious behavior by the men entrusted with protecting President Obama seemed clear-cut. Members of Congress and tabloids depicted a dozen agency employees meeting prostitutes in their hotel rooms and drunken revels at brothels or strip clubs involving up to 20 women.
But now, as the Secret Service pursues an inquiry involving interviews with hotel maids, the women involved and the roughly 200 agents and officers assigned to Mr. Obama’s trip to Colombia, the investigators have pieced together a more nuanced story, complicating how the senior agency managers addressed the fates of their employees, according to two officials briefed on the findings.
One official said that the misconduct in Cartagena, Colombia, ranges from personnel — including at least one veteran supervisor — who knowingly took prostitutes to their hotel rooms to at least two employees who had encounters with women who investigators now believe were not prostitutes. One officer, who is single, met a woman who investigators concluded was not a prostitute in a chance encounter at a bar before taking her to his room, according to the official.
Another, who was cleared of serious misconduct but will face disciplinary action, had taken a woman to his hotel unaware that she was a prostitute until she demanded money, the official said. The man refused to pay and told her to leave, the official said.
On Tuesday, the Secret Service announced that two employees under scrutiny would remain with the agency, two had resigned and proceedings to dismiss another had begun. Of the dozen originally implicated, a total of three will remain; six have resigned; two have been dismissed; and one has retired.
“This scandal itself was the worst moment in the history of the Secret Service,” Representative Peter T. King, the chairman of the House Committee on Homeland Security, said Tuesday. “But in the span of 12 days they have moved very quickly and aggressively on this,” and will continue the inquiry to make sure that national security was not compromised.
The agency’s investigation, which also included polygraph tests of the employees, has been conducted amid intense attention from the news media and Capitol Hill. The Secret Service also is looking into whether there has been a pattern of misconduct on presidential trips to foreign countries.
Some former officials questioned the rigor of the investigation into the activities of those on the Colombia trip, who included men from dog-handling, sniper and counterassault units.
Glenn A. Fine, the inspector general for the Department of Justice from 2000 to 2011 and now a defense lawyer in Washington, said that the fact that the investigation was conducted by the Secret Service — and not an inspector general — raised questions about the credibility of the findings.
“An inspector general’s office, unlike the Secret Service, doesn’t have an interest in the outcome,” Mr. Fine said. “The Secret Service wanted to move quickly on this to show that they were taking care of it.”
The investigation was complicated by the Secret Service’s rules of conduct that do not appear to clearly address the issue of whether their employees — most of them are male — can spend the night with a woman in a foreign country.
On Tuesday, a spokesman for the agency declined comment when asked about the regulations. A government official who had been briefed in recent days by Secret Service officials said that agency officials could not answer the question of whether that conduct violated agency rules.
“They said ‘We teach all our agents that if they go to Amsterdam, they cannot smoke marijuana,’ ” the official said. “But they couldn’t tell us whether there was anything explicit in their rules and regulations that said anything about whether one of their personnel could spend the night with a woman in a foreign country. They said they would have to get back to us on that and they haven’t.”
In forcing out some of the personnel, the agency made the case that some of the employees had jeopardized their national security clearance by their interactions with the women, according to the official. Without clearances, they could not perform their jobs.
In North Carolina on Tuesday, President Obama called the Secret Service agents caught in a prostitution scandal “a couple of knuckleheads” who did not reflect the overall professionalism of the agency.
“The Secret Service, these guys are incredible,” Mr. Obama said at a taping of Jimmy Fallon’s late-night show on NBC on the campus of the University of North Carolina. “They protect me, they protect our girls. A couple of knuckleheads shouldn’t detract from what they do. What they were thinking, I don’t know. That’s why they’re not there anymore.”
The Secret Service has found no evidence that the women who spent the night with the personnel were foreign agents or that the women were exposed to classified information, according to government officials.
Nonetheless, members of Congress continued to raise the issue on Tuesday. In a radio interview, Senator Charles E. Grassley, Republican of Iowa, said countries may be using prostitutes to obtain information about the United States and that the Russians were famous for using such tactics.
The United States military has said that 11 enlisted personnel on the Colombia trip are also under investigation, and at least half of them had violated curfew. But there are no accusations of involvement with prostitutes.
In an echo of the Colombia situation, Defense Secretary Leon E. Panetta said on Tuesday that three United States Marines acting as security guards and one embassy staff member at the American Embassy in Brazil had been disciplined and sent home around Christmas 2011 after they became embroiled in a dispute with a prostitute at a Brasília night club.
According to an American Defense Department official who asked for anonymity because he was discussing sensitive information, the Marines got into a car with the woman and then disagreed over her payment. In the process the Marines pushed the woman out of the car, breaking her collarbone, the Defense official said.
After a Navy investigation, all the Marines were disciplined, with two being reduced in rank. The case has been well covered in the Brazilian news media, and Mr. Panetta, who was in Brazil on a weeklong visit to the region, was asked about it by a Brazilian reporter at the news conference.
“This incident was fully investigated and those that were involved have been punished and held accountable,” Mr. Panetta responded. “They are no longer in this country, they were reduced in rank and they were severely punished for that behavior. I have no tolerance for that kind of conduct.”
The Defense official said that the American Embassy paid the Brazilian woman’s medical expenses. But the woman decided to sue the embassy after the incident in Cartagena.
Elisabeth Bumiller contributed reporting from Brasília.
This article, "," first appeared in The New York Times.