The Secret Service is bracing for the impending appointment of a new director with a senior military rank, the first time an agency chief would come from outside the service in modern history.

Agents and officers are expecting Department of Homeland Security Secretary John Kelly, a retired Marine general and former head of U.S. Central Command, to tap another general to head the Secret Service and help reform the agency and impose more rigorous and even-handed discipline, according to two knowledgeable sources.

President Trump's appointment of a general to the top Secret Service post, at the behest of Kelly, is expected to take place soon – with employees anticipating an announcement some time in the next week. Former Director Joseph Clancy retired from the agency for a second time March 3, and acting director William Callahan has taken on the top leadership role over the last three weeks in his absence.

As soon as Clancy left, a spate of serious security lapses and misconduct cases occurred, the most serious of which involved a March 10 fence-jumping incident in which the jumper was able to meander around the White House South Lawn for nearly 17 minutes without being detected.

The 26-year-old man, identified as Jonathan Tran, was detained only after he made it to the back door of the White House, jangled the doorknob, and announced that he had an appointment with the president.

Six Uniformed Division officers are facing discipline for their inability to detect and find the intruder that night, the sources confirmed. The agency has launched an investigation into the incident through its Office of Professional Responsibility, its internal office for looking into possible misconduct.

It is not known whether that investigation will delve into allegations that alarm sensors on one of the fences the jumper managed to overcome were removed and not reinstalled when Secret Service employees raised the height to provide better protection from intruders.

The Washington Examiner first reported that Tran was able to scale a particular fence without setting off alarms because they had been removed, leading to confusion among officers about his whereabouts and whether an intruder was indeed inside the White House complex.

A decision to remove the detecting devices and not reinstall them would likely involve at least one senior manager, and agents and officers want to know whether the person or persons who made that decision will face discipline along with the Uniformed Division officers who failed to detect the intruder.

The Secret Service in recent years has a recent history of uneven punishment. Agents and officers describe a "culture of corruption" in which senior officers close to the 8 th floor at headquarters, where the top managers have their offices, often escape the same disciplinary measures rank-and-file agents and officers would for similar misconduct.

The uneven discipline and tight-knit atmosphere at the agency has contributed to severe morale problems that have led to an exodus of agents and officers to other government agencies.

President Obama in early 2015 brought in Joseph Clancy, a former member of his own protective detail who had retired to head security for Comcast. Both Obama and congressional leaders had hoped he could resolve the discipline and morale problems.

But in a 2016 employee survey, the service ranked 305, dead last in a survey of job satisfaction conducted annually by the non-partisan Partnership for Public Service. The agency's ranking fell in 2016 for the fifth straight year.

The recent string of security lapses and misconduct comes in the middle of a turbulent political climate in which President Trump's loyalists fear security threats against him could be rising.

In addition, the Secret Service has suffered a string of embarrassing mistakes over the past month. In one, a special agent had her laptop with floor plans for Trump tower stolen out of her car in Brooklyn overnight. In another, two senior agents took photos of Trump's sleeping eight-year-old grandson.

In January, the Examiner first reported that the top agent heading the agency's Denver District posted on Facebook before the end of the presidential campaign that she would rather face "jail time" than take "a bullet" for Trump. The agent has been removed for the Denver post and is on administrative leave pending the outcome of an internal investigation.

In late 2014, an independent blue-ribbon panel formed to evaluate security lapses and problems within the service called for an "outsider" to be named to head the agency.

In recent weeks, Rep. Jason Chaffetz, R-Utah, and Sen. Ron Johnson, R-Wis., who both chair committees with Secret Service oversight responsibilities, have called on Trump to name an outsider after Clancy announced his departure.

Sen. Claire McCaskill, D-Mo., however, told the Washington Examiner that an "outsider" should not be appointed just for the sake of being an "outsider."

"We've got too much of that going on right now," she said in reference to a number of Trump's Cabinet selections from the private sector.

An Examiner analysis of Secret Service directors could not find one, dating back to at least President Truman, that did not rise through the Secret Service ranks to become director.

Allan Pinkerton, who founded his own detective agency and was the original head of what would become the Secret Service, became famous after thwarting an early plot to assassinate President-elect Abraham Lincoln.

Lincoln later hired him and several of his agents to help protect him during the Civil War.