Secret Service Director Randolph Alles speaks during a news conference Oct. 26, 2018, at the Department of Justice in Washington. (Andrew Caballero-Reynolds/AFP/Getty Images)

U.S. Secret Service Director Randolph D. “Tex” Alles will be stepping down from his post, the latest in a string of departures from President Trump’s administration.

Alles “has done a great job at the agency over the last two years, and the President is thankful for his over 40 years of service to the country,” White House press secretary Sarah Sanders said in a statement. “Mr. Alles will be leaving shortly and President Trump has selected James M. Murray, a career member of the USSS, to take over as director beginning in May.”

The departure of the Secret Service chief comes amid a broader shake-up in the Department of Homeland Security. On Sunday, Trump announced that Homeland Security Secretary Kirstjen Nielsen would be stepping down. Last week, Trump said he was rescinding his nomination of Ronald Vitiello to be director of Immigration and Customs Enforcement, saying he wanted to go in a “tougher” direction. Both Alles and Vitiello reported to Nielsen.

Security protocols around Trump have come under scrutiny in recent days after an apparent security breach at the president’s Florida resort.

Secret Service agents arrested a Chinese woman after she gained access to the reception area of the Mar-a-Lago Club late last month, saying they found she was carrying two passports and a thumb drive containing malicious software, according to court documents. Prosecutors say the woman, Yujing Zhang, first approached a Mar-a-Lago security checkpoint March 30 and told security officials she was there to go to the swimming pool.

Management at Trump’s Palm Beach property, where individuals pay a fee to obtain memberships that can provide proximity to the president, allowed the woman to bypass security, prosecutors said. Zhang was ultimately stopped after a receptionist questioned her.

Trump said that the incident was a “fluke” and that security at his Mar-a-Lago resort is sufficient.

“I could not be happier with Secret Service,” Trump told reporters at the White House on Wednesday. “Secret Service has done a fantastic job from day one. Very happy with them.”

The Secret Service issued a statement after the woman was caught, appearing to lay blame for the security breach on management at Trump’s club.

“The Secret Service does not determine who is invited or welcome at Mar-a-Lago; this is the responsibility of the host entity,” the agency said.

CNN first reported that Alles was being ousted from the administration.

How many days has it been since a high-profile departure from the Trump administration?

Trump selected Alles, a retired Marine Corps general and former acting deputy commissioner of Customs and Border Protection, in 2017. He was the first Secret Service director in at least 100 years not from the agency’s ranks.

After his departure was made public Monday, Alles sent a message to the Secret Service workforce saying it was “not the case” that he had been fired by Trump.

“The President has directed an orderly transition in leadership for this agency and I intend to abide by that direction,” Alles said. “It is my sincere regret that I was not able to address the workforce prior to this announcement.”

In a conversation with Alles about two weeks ago, acting White House chief of staff Mick Mulvaney said there would be “transitions in leadership” throughout DHS, according to a DHS official who was not authorized to speak publicly.

After the discussion with Mulvaney, which took place before the Mar-a-Lago security incident, there were no further talks on the subject until Monday, when reporters started calling the Secret Service to say they were hearing Alles was being forced out, the official said.

“Secret Service employees are shocked, bewildered, it’s just very unexpected,” said the DHS official. “There has been no contentiousness, everything has been fine, but the director and the president had no past connection, and they wanted changes throughout DHS.”

Murray, who began at the service in 1995 and serves as assistant director for the Secret Service Office of Protective Operations, plans to take over as director next month.

Sen. Charles E. Schumer (D-N.Y.) released a statement Monday calling for Alles to testify before Congress concerning Mar-a-Lago and any security issues the president’s club poses, as well as other matters.

“The outgoing Secret Service director Randolph “Tex” Alles must testify before Congress as soon as possible about the potential security vulnerabilities at Mar-a-Lago involving a Chinese national arrested with malware, and other counterintelligence and national security threats,” Schumer said in the statement.

Rich Staropoli, a former Secret Service agent and former senior Homeland Security Department official under Trump, said the president appears to be booting several key people who got their jobs at the urging of former White House chief of staff John F. Kelly.

“He was pushed by John Kelly,” Staropoli said. “The president likes generals. But now it looks like he’s cleaning house.”

Staropoli said the number of changes in directors at the service is dizzying.

“The Secret Service is a culture that doesn’t handle change too well,” he said. “To keep changing directors — this guy’s only been there two years — isn’t a good way for the Secret Service to operate.”

“This feels like getting rid of all of the friends of Kelly,” said Jonathan Wackrow, a former member of President Barack Obama’s detail.

Wackrow said Alles was heralded as the first “outsider” who would have a better shot at addressing major security and misconduct problems that had plagued the service during the Obama administration and the early part of Trump’s tenure. But he hasn’t been able to fix some of the service’s long-standing problems, Wackrow said, including difficulty in hiring and retaining officers who help patrol the White House.

“He got immediately tainted by the inside,” Wackrow said. “He had to get his institutional knowledge from the people who caused the problems over the years.”

Devlin Barrett and David Fahrenthold contributed to this report.