I wasn’t surprised to learn that David Fein tendered his resignation and will soon step down from his latest incarnation as U.S. Attorney for Connecticut. Word on the street has always been that he would be a one-term occupant of that office. His eyes were said to be on a far greater prize, perhaps a federal judgeship, or maybe a more senior perch in the second Obama administration.

But opportunities for advancement apparently did not materialize, so he’s returning to private practice, or so he says. This gives the president an opportunity to appoint a new top federal prosecutor for Connecticut. He should choose carefully. The office is in need of fixing. The new U.S. Attorney needs to repair the damage done in the past four years.

Every top dog has the right to surround himself with the pups of his choosing. When Mr. Fein took control of the Justice Department’s Connecticut kennel, he had a distressing tendency to choose prosecutors animated by the attack-dog style of the Southern District of New York. There’s almost a cultural divide in the office: the red meat goes to the young firebrands; everyone else, the old hands, in particular, got the leavings.

The result was an office transformed in small ways that mattered.

Under the old regime, a target under investigation had the option to turn himself in when, and if, a grand jury returned an indictment. Mr. Fein changed that. Prosecutors would mutter apologies about the new policy. The office would not strike deals to permit folks to turn themselves in. Instead, agents would bang on the door of the unsuspecting early in the morning, even for white collar cases.

I’ve had the wife of more than one client in tears as she relayed to me how armed federal agents demanded entry in the bedroom of sleeping children just after dawn — this after the man of the house, accused of a white collar crime, was already in cuffs and on his way out the door. This isn’t law enforcement; it is thuggery. I lay responsibility for that at the paws of Mr. Fein.

All at once, the office seemed to have fallen in love with criminal complaints as a means of initiating an arrest. These decisions seemed driven less by the exigencies of public safety than by tactical gamesmanship. A client could demand a probable cause hearing after such an arrest, but if you made such a demand, you might well be threatened with indictment on more serious charges. The grand jury became less a protection of people from rogue acts of government agents than it did an investigative tool and a club to be used against those took too robust a view of their rights under the federal Constitution. That, too, has Mr. Fein’s paw marks on it.

And what of the emasculation of line prosecutors? All at once, it seemed as if Mr. Fein’s top dogs had to approve of each and every plea deal in the district. I negotiated a deal with one line prosecutor in a difficult case. We waived a probable cause hearing after being told that failure to do so might yield more significant charges and enhancements for aggravating factors. After months of talks, we agreed to a deal. "No deal," we were told, and then the client was slapped with every sentencing enhancement the government could apply. When I complained about equity, I was told, with a straight face, I could have my probable cause hearing if I wanted it.

The old guard in the office was pushed to the side. You could hear them yowling sometimes, consigned as they were to the backrooms of Justice’s kennel. New attack dogs set a more aggressive tone.

I am not sure that justice has been done in Connecticut in the past four years. Yes, there have been plenty of prosecutions. But that would have been the case even had Mr. Fein’s office remained vacant.

What was strained in the past four years was collegiality among members of the defense bar and the prosecution. More damaging, a sense arose that prosecutors were suddenly more concerned with convictions and big sentences than they were with seeing that justice was done.

The president has a chance to set a different tone and direction in Connecticut’s United State’s Attorney’s Office. Mr. Fein’s tenure was not a high point in the office’s history. The new top dog needs better manners, and a greater respect for the leash imposed by due regard for the rights of the accused and their families.•