Neil H. MacBride, U.S. attorney for the Eastern District of Virginia, is seen during a press conference outside the federal court in Norfolk, Va., on Aug. 18, 2011. (Steve Helber/Associated Press)

U.S. Attorney Neil MacBride — whose office is in the national spotlight as it investigates Virginia Gov. Robert F. McDonnell and those in the WikiLeaks organization — told staff members Thursday that he plans to leave his post in the Eastern District of Virginia next month.

The announcement, which comes as MacBride nears four years in the office, will almost certainly raise questions about the status of those investigations and how they might proceed without the seasoned attorney’s hand to guide them. Friends said that MacBride previously delayed his departure because of the ongoing investigations.

But ultimately, the friends said, MacBride decided that the cases were in good hands. He was ready to try something else — although he does not have another job lined up.

“You got WikiLeaks, you got the governor, you can just go online and see how many major cases he’s handling,” said Ken Wainstein, a defense lawyer and friend who worked with MacBride in prosecuting homicide cases in the U.S. attorney’s office for the District of Columbia. “The reality is, though, he’s always going to be in the middle of some big investigations.”

Former federal prosecutors and other legal experts said MacBride’s departure probably will not have an impact on the high-profile cases.

“It’s the nature of federal prosecutions, particularly in the higher-profile jurisdictions, for investigations and cases to transition from one administration to the next,” said Jacob Frenkel, a former Securities and Exchange Commission enforcement lawyer who now works in private practice. He said a decision to charge the governor, in particular, would probably require a “high-level sign off” from the Justice Department, even if MacBride were to have stayed.

A ‘dream job’

MacBride, 47, a graduate of Houghton College in New York and the University of Virginia law school who lives with his wife and three children in Northern Virginia, declined to be interviewed for this article. But in written responses to a reporter’s inquiries, he said he is leaving a “dream job” and is planning on “taking a big chunk of time off to be with my family.”

“I’m looking forward to my next professional challenge,” he said in a statement.

MacBride told staff members that his resignation will take effect at midnight Sept. 13. His office has about 300 lawyers and other employees working in ­offices in Alexandria, Richmond, Norfolk and Newport News.

Typically, a departing U.S. attorney is replaced by a first assistant until the president appoints a permanent successor. But MacBride’s first assistant, Dana J. Boente, was appointed in December to serve as the interim U.S. attorney for the Eastern District of Louisiana after the longtime U.S. attorney there resigned amid revelations that his two top deputies were posting online comments about subjects of the office’s investigations. It is unclear whether Boente will come back to the Eastern District of Virginia or whether the acting first assistant, Kathleen Kahoe, will take over.

Those close to MacBride and other legal experts praised his work as U.S. attorney, saying he elevated an office that already had enjoyed national prominence. Former deputy U.S. attorney general Jamie Gorelick, a longtime friend who is now in private practice, said MacBride was “clearly viewed as one of the stars” of the Justice Department. She said he had planned to leave earlier but stayed because of a handful of prominent cases and because of his first assistant’s departure for New Orleans.

“From his wife’s point of view, I think he’s overstayed,” Gorelick joked.

Attorney General Eric H. Holder Jr. said in a statement that MacBride is “an exceptional leader, a committed public servant, and a brilliant attorney.”

“I am certain that his enduring contributions, his many achievements, and his fine example will guide the men and women who serve the Eastern District for years to come,” he said.

Security cases

The Eastern District of Virginia — home of the CIA and the Pentagon — has long played host to some of the nation’s most high-profile terrorism and national security cases, including the trial of Zacarias Moussaoui, a conspirator in the Sept. 11, 2001, attacks. Federal officials do not hesitate to fly international criminals into Dulles International Airport so they end up on the district’s rocket docket. And because SEC servers are housed in Alexandria, prosecutors for the Eastern District of Virginia often end up handling some of the country’s most complicated financial fraud cases.

Before he was confirmed as U.S. attorney in September 2009, MacBride worked as an assistant U.S. attorney in the District and as an associate deputy attorney general at the Justice Department. He also worked as Vice President Biden’s chief counsel when Biden was chairman of the Senate Judiciary subcommittee on crime and drugs.

In Virginia, MacBride had seemed to focus on cyber and international crimes, although he did not neglect the district’s bread-and-butter ­cases involving financial fraud, public corruption and gang-related crime.

MacBride notably won convictions against 26 Somali pirates, including three who recently learned that they would receive life sentences for their roles in the fatal shootings of four Americans on a yacht off the Horn of Africa. He successfully prosecuted several terrorism suspects, including Amine El Khalifi, who threatened to bomb the U.S. Capitol, and Farooque Ahmed, who threatened to bomb the Metro system. And his office is pursuing what they call one of the largest intellectual property infringement cases in U.S. history against the popular file-sharing Web site

But even bigger ­cases might be down the road.

This week, attorneys for McDonnell (R) and his wife huddled with prosecutors in the U.S. attorney’s office in an effort to convince them that Virginia’s first couple should not face criminal charges in a rapidly escalating public corruption probe.

MacBride is also walking away from the office at a time when it would be responsible for prosecuting Edward Snowden, the former National Security Agency contractor who leaked a trove of documents about top-secret surveillance programs, and Julian Assange, the founder of the WikiLeaks organization, in the event either man made his way to the United States.