Members of the Secret Service follow President Obama in October as he arrives at Northwestern University in Evanston, Ill. (Brendan Smialowski/AFP/Getty Images)

The Secret Service is forcing out four of its most senior officials while two others are retiring — the biggest management shake-up at the troubled agency since its director resigned in October after a string of security lapses.

The departures will gut much of the Secret Service’s upper management, which has been criticized in recent months by lawmakers and administration officials who say it has fostered a culture of distrust between agency leaders and its rank-and-file and made poor decisions that helped erode the quality of this once elite agency.

Acting director Joseph P. Clancy on Tuesday informed the four assistant directors who oversee the Secret Service’s core missions of protection, investigations, technology and public affairs that they must leave their leadership positions.

If they do not resign or retire, they can report for a new assignment with the Secret Service or its parent agency, the Department of Homeland Security, according to people familiar with the discussions.

“Change is necessary to gain a fresh perspective on how we conduct business,” Clancy said in a statement to The Washington Post. “I am certain any of our senior executives will be productive and valued assets either in other positions at the Secret Service or the department.”

Changes in the Secret Service

The departures of six out of the agency’s eight assistant directors follows a scathing report last month by a DHS-appointed panel that concluded the agency is suffering from low morale among the rank-and-file and is “starved for leadership.”

Clancy cited the DHS review, as well as “my own assessments,” in making his decision this week.

Yet he stopped short of a total house cleaning. The agency’s longtime second-in-command, Deputy Director Alvin T. Smith, who has been a central decision-maker under the past three directors, remained in his post. Smith oversaw budget decisions and agency priorities during a time that many officials now say overlapped with the Secret Service’s slow and steady decline.

And while the DHS panel urged that the White House choose an outsider to be the agency’s next permanent director, Clancy, the former head of President Obama’s protective detail, has indicated to colleagues that he is willing to stay on if Obama wants him to do so.

Clancy, who assumed his current job after the October resignation of Director Julia Pierson, declined to respond to questions about his plans for the agency or how he will fill the vacant leadership posts.

Rep. Jason Chaffetz (R-Utah), chairman of the House Oversight and Government Reform Committee and a vocal critic of Secret Service managers, said Wednesday that the changes were not enough.

“It’s a good start, but they are by no means done,” Chaffetz said. “There are more senior staff that need to be reviewed and probably changed.”

The Secret Service is reassigning top brass after a series of missteps. From a White House intruder to exploits with Colombian prostitutes, here’s a look at other Secret Service scandals. (Gillian Brockell and Jackie Kucinich/The Washington Post)

Rep. Michael McCaul (R-Tex.), chairman of the House Homeland Security Committee, said he was pleased that Clancy “took a hard look at the leadership of the agency and is taking the necessary steps to improve.” McCaul urged the Secret Service to “bring in leaders from outside the agency with strong management experience” and said his committee would make oversight of the Secret Service a priority.

Lawmakers and administration officials lost confidence in the Secret Service’s top management amid a series of embarrassing lapses and revelations last year. In September, a knife-wielding man scaled the White House fence and ran through much of the mansion’s main floor. Also that month, an armed private security contractor in Atlanta was able to board an elevator with Obama. Lawmakers were also outraged over a series of revelations in a Post report about the agency’s bungled response after a gunman shot at the White House in 2011.

Clancy told lawmakers in November that a desire for management to win back the trust of agents and officers was “an integral part of why I agreed to return.”

On Wednesday, former Secret Service officials said the changes were momentous and, in large measure, a necessary step toward restoring the Secret Service’s reputation.

Bill Pickle, a former deputy assistant director, said Clancy was in a difficult position.

“He is being pressured to take action by DHS, and these assistant directors are his friends,” Pickle said. “But he knows that it’s for the good of the organization that these people move on. It’s not a happy moment, but it’s time to retire.”

Agents and officers have complained for years that the Secret Service’s upper management was insular and more interested in shielding itself from problems than rewarding good work. By creating so many vacancies, some officials said, Clancy could be making room for younger people to move up in the ranks and bring a fresh perspective.

“Let’s start bringing in and grooming the lower level,” Pickle said. “They have a very strong bench internally.”

The four assistant directors who were told to leave are Dale A. Pupillo, a former head of Vice President Biden’s protective detail who oversees protective operations; Paul S. Morrissey, who oversees investigative operations; Jane P. Murphy, who leads governmental and public affairs; and Mark Copanzzi, who oversees technology and the tools for mission support.

Victor Erevia, who headed Obama’s detail and was named assistant director for training in 2014, announced that he would retire this year in the wake of the panel’s findings. An official familiar with his departure said he had been seeking a job in the private sector for some months.

Gregory A. Marchio, the assistant director for the Office of Professional Responsibility, also announced last month he was retiring after reaching the mandatory retirement age of 57. Senior executives have typically been granted a waiver if they wish to remain in the agency.

The Post reached out to each of the assistant directors, and all but one declined to comment.

Copanzzi stands out for being new to the Secret Service executive ranks, though he served in the agency for 32 years. He became assistant director over technology just a few weeks before the September fence-jumping incident. He told The Post in a written statement that he respects “the prerogative of the Director of the Secret Service to choose his [senior executives]; as such I have been given an opportunity to take an executive position at another DHS component.”

Rep. Elijah Cummings (D- Md.), ranking member of the House Oversight and Government Reform Committee, said in an e-mailed statement:

“It is imperative that the Secret Service succeed in its mission to protect the President, our nation’s elected officials, and foreign leaders from around the world, and the independent review panel raised significant concerns about the ability of the agency’s current leadership to fulfill these objectives.  It is now time to work together to move this agency forward.  I sincerely hope new leadership with the help of Congress will turn the page, restore full trust in the agency and implement real, much-needed reforms.”