When Warren Montgomery stands in front of the imposing St. Tammany Justice Center on Monday morning for his inauguration, his hand on a Bible held by his mother, he will be the first new district attorney in 30 years to be sworn into office in the 22nd Judicial District.

That fact alone is a profound change for the criminal justice system in St. Tammany and Washington parishes. But what’s unfolding in the office Walter Reed owned for decades is more fraught than a typical transition, given the fact that the office is being investigated by a federal grand jury and the state Legislative Auditor’s Office.

“It’s going to be the same challenge any newly elected public official would have in assuming control of any office,’’ said Rafael Goyeneche, president of the Metropolitan Crime Commission. “It’s complicated by the problematic culture of the District Attorney’s Office that this new DA is going to have to change.’’

Peter Strasser, a longtime friend and former colleague of Montgomery at the U.S. Attorney’s Office, had a more colorful take: “The morning after the election, he must have said, ‘Oh my God, what have I done to myself?’ It’s like Hercules having to clean out the Augean stables.’’

Montgomery, 59, indeed has been at work in the weeks since his Dec. 6 runoff victory, not with a shovel but with a transition team that has reviewed the inner workings of the office. Their reports provide the underpinnings for the policies and procedures he will implement when he begins work Monday.

Those rules of the road will be in writing — something that was not true under Reed.

Assistant district attorneys, who were allowed to maintain outside legal practices under Reed, will be discouraged from doing so by their new boss. He doesn’t want to prohibit staffers from handling what he called “innocuous’’ legal matters, he said, but any work they do will have to be vetted and approved on a case-by-case basis by an ethics advisory committee that will ensure there are no conflicts of interest or other problems, Montgomery said last week.

“He had a really good transition team, some good people, who did a lot of good work,’’ said Goyeneche, who has met with the new DA. But those team members were dealing with people who, during that period, were still answerable to Reed, Goyeneche pointed out.

“You never really get a complete picture until you are in that chair and everyone is reporting to you,’’ he said.

While anyone succeeding a 30-year incumbent would face challenges, Montgomery must do the job in “a more effective and transparent manner,’’ Goyeneche said. “He’s got his hands full.’’

Structural change

Montgomery is making a structural change to the office with the creation of three divisions, each to be headed up by a chief. Tony LeMon will head the civil division. Two federal prosecutors that Montgomery hired away from the U.S. Attorney’s Office, Collin Sims and Tony G. Sanders, will be over the criminal and administrative divisions, respectively.

State law requires DAs to have a first assistant, and LeMon will have that title, but he will not be above the other two chiefs in the office hierarchy, Montgomery said, and will not function as a first assistant in the day-to-day operations of the office.

The new boss has been interviewing the office’s existing staff and reviewing résumés submitted by people who want to come work in the office.

How rigorously Montgomery will clean house remains unclear, although some of Reed’s staff members already have left, notably his first assistant, Houston C. “Hammy’’ Gascon.

Another member of Reed’s inner circle, Harry Pastuszek, left at the end of September. His law firm provided legal representation for the St. Tammany Parish School Board, an arrangement made through Reed. Since his departure, David Pittman, who works in Pastuszek’s firm, has been doing that work, School Board spokeswoman Meredith Mendez said.

The practice of having the DA’s Office provide legal representation for local governments and agencies is being looked at by a charter review committee that Parish President Pat Brister has convened; LeMon sits on that committee.

Whether that policy will continue in the future is a decision that Montgomery said the community will make. In the interim, he said, he is talking to officials at those bodies and does not plan personnel changes for the time being.

Financial issues

The DA’s Office under Reed has wrestled with budget shortfalls. In recent years, Brister has said, Reed’s administration has been coming back to the parish midyear to say it needed more money. In August, she asked the state Legislative Auditor’s Office to conduct a “thorough and complete inspection’’ of the finances in Reed’s office. At the time, she said the public needed to know whether alleged shortfalls were the result of increased costs and demands for services or of “misuse or unethical practices.”

She also pointed to the upcoming change in administration, saying Reed’s successor needed a clear picture of the office’s finances.

Brister has met with Montgomery’s transition team, and she said her hope for the new administration is that there will be open dialogue between that office and hers and more conversations.

As for the federal probe, she said oversight is necessary for people to have trust in government.

Montgomery said last week that his transition team has gone over the finances at the office. “Monies have not been misappropriated or misallocated in the District Attorney’s Office. Certainly there have been excesses,’’ he said, pointing to a lucrative special retirement plan that Reed put in place for some of his inner circle for a period of time. “To the best of my knowledge, there’s no missing money,’’ he said.

He demurred at saying whether he believes excesses in the office also ran to salaries.

“Every manager who comes into an organization is going to have a different opinion on who should be paid how much, and so it’s natural for me to feel there should be adjustments in salaries,’’ he said.

He said salaries should be tied to productivity, and it’s too soon to make those determinations. However, he said, assistant district attorneys will not be evaluated primarily on the number of jury trials. He called “pick and pleas” — which involve seating a jury when the prosecutor knows a defendant is going to enter a guilty plea, just to boost trial numbers — a waste of public resources.

As for what Montgomery’s pay will be, he said he is waiting for the Louisiana District Attorneys Association to issue its formula for how much district attorneys should be paid, which is due in March. He said his pay will conform to that, but until then, he plans to maintain Reed’s salary, which he said he understands was about $180,000.

Valuable experience

During his campaign, Montgomery frequently touted his work as a federal prosecutor with the U.S. Attorney’s Office in the early 1980s in arguing that he was best qualified to serve as district attorney.

But Strasser, one of his former colleagues there, points to other experience that the new DA can claim. Montgomery went to Puerto Rico in 2001 to expand his family’s business there, said Strasser, who was working with the U.S. Attorney’s Office there at the time.

While Montgomery is fluent in Spanish, he was starting from scratch with no contacts in a place that Strasser described as rife with corruption. Starting up a business and dealing with that corruption is “the best preparation he could have had,’’ he said.

Strasser spent 11 years with the U.S. Department of State, helping developing countries modernize their criminal justice systems and root out corruption. Montgomery was one of the people he called on to conduct training sessions in places like Malawi and Pakistan.

“I can count on one hand the people I implicitly trust, and Warren is one,’’ he said.

Montgomery describes himself as optimistic as he takes office, and he predicts a change in the climate of the office.

“The workers in that office are going to have a quicker step,” he said, “not because somebody’s got a whip on them, but because they’re going to feel that some much-needed change has been brought to the office, and people are going to be rewarded based on their effort and productivity and not based on political considerations.’’

Follow Sara Pagones on Twitter, @spagonesadvocat.