On the afternoon of July 18, 1990, James Leeper, a newly minted homicide prosecutor in Brooklyn, had to make a challenging closing argument. The man he had charged with murder had mounted a substantial defense—offering plane tickets and video footage indicating he had been vacationing at Disney World when a man named Darryl Rush was shot dead in front of a Brooklyn housing project. Leeper acknowledged to the jury that it seemed like the "perfect alibi."

Nonetheless, Leeper confronted the defense straight on: Yes, the defendant, a man named Jonathan Fleming, could have been in Florida around the time of the murder, Leeper conceded to the jury. But Fleming had ample opportunity to fly back to New York, kill Rush and return to his family vacation, Leeper argued. In fact, Leeper told the jury, there were 53 possible airline flights Fleming could have taken to do just that.

Leeper's presentation won the day. The jury returned a guilty verdict. Fleming, 27, was sentenced to 25 years to life in prison.

It took 24 years, but eventually it became clear that there had been much more to Fleming's alibi defense, and that Leeper had failed to disclose it to the jury.

The original case file from 1990 contained a time-stamped receipt showing that Fleming had paid an Orlando hotel phone bill just hours before Rush's murder. The file also contained a letter from the Orlando Police Department informing Brooklyn detectives that Fleming had been seen at the hotel around the time of the killing. By law, Leeper was obligated to turn that material over to Fleming's lawyer. But he had disclosed none of it.

In April, Fleming was set free, the latest victim of a string of wrongful convictions involving the Brooklyn District Attorney's office. But Leeper's role in the case has packed a distinctive mix of shock and dismay.

Interviews with an array of current and former Brooklyn prosecutors, his adversaries in the defense bar, and at least one former Brooklyn judge have uniformly produced glowing testimonials to Leeper's skill, compassion and integrity. People, even those with unflattering views of Leeper's longtime boss, former District Attorney Charles J. Hynes, and the office he ran, find it close to impossible to accept the fact that Leeper knowingly hid vital evidence in a murder case.

"He was universally thought of as a model prosecutor," said Dan Saunders, now a Queens Deputy Executive Assistant District Attorney, who once worked with Leeper in the Brooklyn District Attorney's office. "You'll hear that from everybody. He was a trustworthy and reliable guy. The kind of guy you want to entrust with the difficult work of being a government prosecutor. I hope people say something like that about me one day."

To date, the district attorney's office has said nothing about the Fleming case, other than to acknowledge that its Conviction Integrity Unit had discovered the receipt and additional evidence in recent months. The office offered no explanation for how or why the evidence had remained buried for so long, and, with respect to Leeper's role in the case, has said only that it is "under review."

ProPublica spent several weeks exploring Leeper's career as a prosecutor in Brooklyn, and found an amalgam of genuine respect and personal troubles. Interviews with several current and former colleagues detail his quick, initial rise in the office, but also a long-standing struggle with alcohol. Those interviews with people who worked with Leeper show that eventually his drinking earned him a demotion two years ago.

ProPublica's review also shows that Leeper's career included a 1997 case in which he and the Brooklyn District Attorney's office were accused of withholding evidence that might have established the innocence of a convicted murderer.

In the late eighties, James Leeper was a fast-rising prosecutor known for his fairness and loyalty. Decades later, his alleged misconduct in Fleming's case has shocked colleagues and adversaries alike.

Leeper, in a telephone interview, refused to comment. He did not respond to further requests to discuss the Fleming case, his career or any issues with alcohol.

The reputation of prosecutors in Brooklyn has been battered in recent years.

Earlier this week the New York City Department of Investigation issued a scathing report finding that Hynes, among other violations, received political advice from a top New York state judge and misused public money to fund his ultimately failed 2013 re-election campaign. In a lawsuit, he's also been accused of having long overseen an office of rogue prosecutors, where misconduct was condoned, even encouraged. Hynes has denied the charges in the lawsuit.

One of Hynes's top lieutenants, Michael Vecchione, has been accused of railroading an innocent man on a murder charge, a claim he has vehemently denied. Another senior prosecutor left the office in 2012 after she was accused of having withheld exculpatory evidence in a high-profile rape case that soon was abandoned. Some 90 murder convictions involving the office are under review, many involving a retired police detective, any one of which might hold additional trouble for current or former prosecutors.

For all the accusations and embarrassments, however, few in the New York legal world would have predicted Leeper would be at the center of the latest tumult.

Until last month, Leeper still had a portfolio of cases he was prosecuting. On May 5, he was due in court to make another closing argument in a murder case. The family of 23-year-old Nikita Grebelskiy, a passenger in a livery cab who was shot in the head during a botched robbery, was awaiting justice. Leeper had already laid out all the evidence against 21-year-old Michael Magnan. When he was arrested the night of the crime, Magnan had a .380 caliber shell casing in his shoe, the casing matched the bullet lodged in Grebelskiy's head, a gun found near the crime scene matched both the bullet and the casing, and there was DNA found on the gun that matched the shooter.

All that was left for Leeper to do was sum it all up in one final statement to the jury. But he didn't show up.

He was nearly 40 miles away, in a hospital, recovering from a damaging bout with alcohol, according to numerous current and former colleagues.

"I've never heard of anything like this happening before," said Martin Goldberg, Magnan's defense attorney, who has worked on New York criminal cases for more than 30 years.

Three weeks ago, the Brooklyn District Attorney's office, now run by former federal prosecutor Kenneth Thompson, announced that Leeper had been suspended. The office did not say why, and refused to answer any questions about Leeper's career or his role in any possible misconduct.

Taylor Koss, a former Brooklyn prosecutor who spent years working alongside Leeper, has said Fleming intends to sue—both to learn the truth of what happened and to be compensated for the loss of more than two decades of his life.

"This man suffered behind bars for 25 years because this information wasn't turned over," Koss said.

A Pupil Becomes a Foil

Taylor Koss joined the Brooklyn District attorney's office in September 2001. He was a young, ambitious lawyer, eager to realize his long-held dream of being a top prosecutor, one that he said harkened back to his teen-age days watching hours of Law & Order on television.

James Leeper was one of Koss's early bosses and mentors. At the time, Leeper was running one of the most active bureaus in the office. Prosecutors in it handled nearly all criminal prosecutions in some of the most violent areas of Brooklyn, and the unit was known officially as the "Red Zone." Koss said he wanted to shine there, and saw in Leeper a man to impress and to learn from.

"He had a reputation for being a very strong homicide prosecutor, that he earned it, as opposed to others who were thought of as being political appointees," Koss said of Leeper. "People respected Jim for being a workhorse who earned his spot."

“I wanted him to trust me because I wanted to be in his good graces. People wanted him to think you were a good D.A.” – Taylor Koss, former Brooklyn prosecutor Twitter Facebook Link

Leeper himself had already been in the Brooklyn office for 14 years. He, like Koss, had his heart set on being a prosecutor in his first years out of law school. So much so that he applied twice, enduring a rejection by the Brooklyn office's top brass in 1985, according to the office's personnel records.

"An [assistant district attorney] plays two vital roles in society," Leeper wrote as part of his second, successful application. "The position requires one to be an advocate within the criminal justice system as well as a neutral and objective representative of the people in the district in which he or she works."

"In the latter role, one has the responsibility to thoroughly investigate all 'leads' in a case and to approach cases with a non-advocacy, or non-adversary, perspective. In that sense, one of the A.D.A's most important duties is to ensure that a defendant's constitutional rights are preserved and protected."

The letter moved the district attorney's office, then run by former U.S. Representative Elizabeth Holtzman, to hire Leeper away from private practice. By 1990, with Hynes having succeeded Holtzman, Leeper had secured a position as a homicide trial attorney, an impressively advanced assignment for a young man with only three years of experience as a prosecutor.

By the time Koss was christened as a fledgling prosecutor in 2001, Leeper was head of the Red Zone, and "everyone," according to Koss, "wanted to work in the Red Zone."

"It had the coolest people in it. The coolest bosses," said Koss. "It was the place to be and I got it. I got lucky."

Koss reported to Leeper for more than a decade, and he, like so many others who worked under Leeper, revered the man for his fairness and loyalty. Leeper stuck up for younger prosecutors when they made missteps; he took them aside to school them in the art of persuading a jury; he gave them opportunities to challenge themselves.

"He had implicit faith in me, and if you earned that trust, he'd never micromanage," Koss said. "He believed I could handle myself. He only came to see me do one trial. I had a cooperating witness and he came to watch me put him on, and after that he never questioned me again. I wanted him to trust me because I wanted to be in his good graces. People wanted him to think you were a good D.A."

But those who worked with Leeper came to see a troubled side of him, too. In interviews, more than half a dozen lawyers who worked in the office at the time said Leeper's drinking became pronounced, and, as a result, a problem. Two years ago, according to numerous people in the office, Leeper's drinking cost him his title. Personnel records show he was demoted from chief of the Red Zone back to the homicide bureau, but do not list a reason.

The district attorney's office would not comment on the cause for the demotion.

For his part, Koss moved on to his own new job within the office: deputy bureau chief of the Conviction Integrity Unit, a small group of assistant district attorneys and investigators tasked with re-examining old convictions that might have been flawed.

Koss, in his new job, soon found himself in the uncomfortable and unpopular position of reviewing cases handled by prosecutors who had made their marks years before. He says, however, that he came to feel a sense of gratification in the work: finding evidence that might lead to an innocent person's release, rather than a guilty person's incarceration.

Koss's first case wound up widely celebrated. Over a year-long investigation, Koss and his supervisor, John O'Mara, found evidence that an unemployed printer had been wrongly convicted of murdering a beloved Williamsburg rabbi in 1990. Hynes consented to the release of David Ranta following Koss' investigation in March 2013.

"I'm sure people resented me for it, but I didn't really care," Koss said of the unit's work.

In June 2013, three months after Ranta's release, Koss left the office. But he said he had made a critical observation in his last year there, one that would stay with him in the coming months: Murder cases, especially those tried in Brooklyn in the early, bloody 1990s, could be seriously flawed, and so could the prosecutors who handled them.

Newly in private practice, Koss came to learn of an imprisoned man named Jonathan Fleming, and shortly afterward he joined Fleming's bid for freedom. Fleming's case was pending before the Conviction Integrity Unit Koss once helped run, and Koss realized quickly what lay ahead: He'd be challenging the work and perhaps the ethics of his onetime mentor.

The Alibi Defense

This receipt from a Quality Inn in Orlando, Florida, was taken from Jonathan Fleming at the time of his arrest. It suggests he was thousands of miles away from a murder he was convicted of, just hours before it occurred.

Jonathan Fleming didn't have an unblemished record or reputation in Brooklyn in the late 1980s, having racked up a number of convictions, including for robbery and weapons possession.

But the evidence that Fleming was the man who had gunned down Darryl Rush back in 1989, even at the time of the trial, was less than overwhelming.

One witness, a crack addict, had testified that she had seen Fleming shoot Rush. But it was ultimately shown that she had been more than 400 feet from the scene of the shooting and had not been wearing her glasses at the time. Another witness had been so reluctant to testify that he had to be dragged to the witness stand by a court officer.

As a result, Fleming had spent years after his conviction pressing for a re-examination of his case. The crack addict had recanted shortly after the trial. The man who had reluctantly testified turned out to have testified under a false name. New witnesses had emerged saying that another man was the likely shooter.

Fleming's efforts, however, got nowhere. Prosecutors dismissed the recantation and the reliability of the new witnesses. Judges routinely denied his motions for a rehearing.

Then, in the summer of 2013, with the Brooklyn District Attorney's office under fire for a variety of alleged misconduct, Koss's former colleagues agreed to look into Fleming's claims of innocence.

The ex-colleagues unearthed a bombshell: The Fleming case file had been found, and its contents crippled the case against him. There was, among other evidence, the receipt that had been taken off of Fleming's person at the time of his arrest, and it showed he had paid a phone bill at his hotel in Orlando at 9:27pm on Aug. 14, 1989. The murder took place in the Williamsburg section of Brooklyn at approximately 2:15 a.m.

Koss recalled the moment he got word of the discovery made by his old office.

"I was instantaneously nauseous; physically sick to my stomach," he said.

"You want to believe that these mistakes don't happen," he said. "Then, slowly, you come to the realization that these mistakes do happen, and it results in people losing years of their lives."

Koss credits the work of the Conviction Integrity Unit. But the district attorney's office has said nothing about the botched case, other than to consent in court to Fleming's release.

Had the case file been lost? Overlooked? Buried in a police file not shared with prosecutors? Intentionally withheld by Leeper?

James Devereaux was one of the detectives who worked the Fleming case. At the original trial, Fleming's attorney had asked Devereaux several questions about the phone bill receipt, including whether he recalled telling Fleming he'd make a Xerox copy of it. He testified that he had no recollection of a receipt, but, under questioning, conceded it was possible that one existed and even that he had assured Fleming he would make a copy of it. But the receipt was never entered as evidence in the case.

In an interview with ProPublica, Devereaux said he didn't remember the Fleming case, but he was firm about his evidence disclosure practice at the time.

"I'm not in a position to try to put blame on anybody, especially when I don't recall the case," Devereaux said. "But when a case goes to trial, you go to the D.A.'s office with your file and everything goes over to them."

The law is certainly clear about the responsibility for gathering and disclosing evidence. Leeper was the person ultimately responsible for discovering it and turning it over.

Bennett Gershman, a law professor at Pace University and a leading expert on prosecutorial misconduct, wrote a recent column about the case entitled Don't Let the Prosecutor Off the Hook. In an interview, he said prosecutors will often try to deflect blame for evidence disclosure problems onto police.

"But even if we assume it was in the police file and not the district attorney's file, and the prosecutor had no firsthand knowledge of this thing, once the defense attorney says, 'Hey, check this out, this is a major claim of innocence,' the prosecutor has got an obligation to go back to the police and say, 'Do you have this receipt? Did you write a report? Did you ask the hotel if he was there?'

"It goes to what your obligation is as a prosecutor," Gershman said. "Is it to bury your head in the sand? Or is it to follow all possible leads to find out whether this guy is innocent? This wasn't a needle in a haystack; this was something that was right under his nose."

A Prior Offense?

Anne Feldman served 26 years as a judge in Brooklyn, but across those years, she only once exercised the power to set a convicted prisoner free. The prisoner was Julio Acevedo, and the prosecutor whose failure factored in his release was James Leeper.

In 1989, Feldman had presided over Acevedo's initial murder trial. Acevedo had been charged with fatally shooting a man in a housing project hallway in Brooklyn. At trial, Acevedo had claimed that he'd been caught up in an ugly street beef over drugs and had been forced, with his own life threatened, to carry out the deadly shooting.

Acevedo's argument made an impression on Feldman, but ultimately failed to persuade the jury. At Acevedo's sentencing, Feldman said she had "no idea what the real circumstances were" that led him to kill.

"I suspect the truth lies somewhere between what you said and what the district attorney said," Feldman told Acevedo in court.

She then sent him away for 20 years to life.

But the case was back before Feldman eight years later. Something new had come to light: evidence that Acevedo's account—known legally as a "duress defense"—was genuine. A prosecutor in a subsequent, unrelated case had taken testimony from a man who said he was the person who had forced Acevedo to carry out the killing. The man said he had kidnapped Acevedo and ordered him at gunpoint to fire the deadly shots.

Leeper was the prosecutor who took the potentially exculpatory statement. The information—gained in 1992, three years after Acevedo's conviction and five years before his release—was never turned over to Acevedo. The man's account had surfaced in yet another unrelated Brooklyn case, and Acevedo's lawyers had brought it to the court's attention.

Feldman, presented with the new information, didn't waste much time. Acevedo pleaded guilty to a lesser charge and was released.

"I remember feeling that this guy had told a story at his trial that was true and just feeling very good about letting him out," Feldman said in an interview last month with ProPublica.

It remains unclear to this day what Leeper was thinking. The man who had confessed to forcing Acevedo to kill had also admitted to Leeper a long string of violent crimes. As well, Leeper had not previously prosecuted Acevedo and the circumstances of his conviction might well not have been known to him.

There is no evidence Leeper was in any way sanctioned. Feldman, in releasing Acevedo, appears to have only dealt with the new evidence, and not the question of Leeper's apparent failure. Still, a spokesman for the district attorney's office would years later acknowledge the failure to alert Acevedo to the new evidence was a mistake.

The law, after all, requires that information favorable to the defense be turned over by prosecutors as soon as they discover it, even after someone has been convicted.

Dan Saunders, who was a senior homicide attorney in Brooklyn at the time, declined to comment on this particular case, but in an interview he emphasized the importance of sharing such information no matter the timing.

"Whether a case is pending or the person has already been convicted or served their sentence, if we get something exculpatory, there's always an obligation to investigate it and turn it over," he said.

Feldman said Leeper never struck her as the kind of aggressive prosecutor so driven to win that he might break the rules to do so.

"It seemed to me that he was a very upfront guy," Feldman said. "He was not overly zealous; I didn't feel like he was out to kill like some of the other prosecutors out there."

Uncertain Fate

Jonathan Fleming, hugs his attorney Anthony Mayol while his other attorney Taylor Koss applauded in Brooklyn's Supreme court, after a judge declared him a free man. (Bebeto Matthews/AP Photo)

The April 8, 2014, proceeding before Brooklyn Judge Matthew D'Emic was brief, if momentous.

Brooklyn Assistant District Attorney Mark Hale, in consenting to Jonathan Fleming's release from prison after 24 years, quickly laid out the rationale.

"The documentary evidence, and I'm talking specifically about the receipt from the Florida hotel and the interviews with the employees at the hotel…was not available to the defense at trial," Hale told D'Emic. "We uncovered that in an investigation…And it supports the defendant's alibi to such an extent that had it been available at the trial, the likely result of it would've been different. And for that reason we ask that the conviction be vacated."

D'Emic accepted a motion to dismiss Fleming's conviction, and pandemonium ensued in the courtroom.

Reporters from every major newspaper and television channel in New York were there to record an overjoyed Fleming celebrating with his family. His story went viral. A Wall Street banker started an Internet campaign that raised nearly $50,000 to help Fleming get back on his feet; the donations came from more than 600 people in at least 14 different countries.

But little was said about Leeper. Few news articles even mentioned his name. And he went on prosecuting a full load of cases.

Less than a month ago, at least five of his cases were moving toward trial, according to court records. They included the case against Magnan, the young man arrested with a casing in his shoe that matched a bullet in a murder victim's head, and another, thornier case involving the alleged murder of 50-year-old Robert Reichl.

According to 2013 news accounts, Reichl was lured to the roof of an apartment building in the Sunset Park neighborhood of Brooklyn with the promise of sex for money. Allegedly, a group of men attacked him, stole his money, and pushed him off the roof. Three men have been charged in the crime, but at least two claim they're innocent.

Howard Greenberg, an attorney representing one of the accused, said he'd come to know and respect Leeper over the years. Greenberg said if Leeper is proven to have intentionally withheld evidence in the Fleming case, he will have no sympathy for him. But until then, Greenberg said he was not uncomfortable with Leeper continuing to try cases.

"He's a guy that I like and I have found to be above board," Greenberg said. "But let's put it this way, anyone who knew something like that was there and didn't turn it over is going to hell. I'm not pulling punches."

The lack of sanctions against New York prosecutors shown to have engaged in misconduct has been the focus of a ProPublica investigation for more than a year. The investigation found that such prosecutors almost never endure real punishment for their lapses, even when their misconduct is so egregious that it lands the innocent in prison.

Kenneth Thompson, Brooklyn's new district attorney, had pledged during his 2013 campaign that he would rehabilitate the office's reputation on wrongful convictions. And since taking the helm in January, he seems serious about keeping his word. He's vacated the convictions of six people prosecuted under Hynes and he's named some respected legal minds to establish his own version of the Conviction Integrity Unit. He has hired Ronald Sullivan, a Harvard legal ethics professor, to lead the effort.

But to date, there has been no word on Leeper's fate for his role in the Fleming case, a state of uncertainty that has only added to the confusion among his many admirers.

"I worked with him and for him, and I'd do it again," said one former colleague. "He was intelligent, he understood how to try cases, and he was fair — never a win at all costs kind of guy."

For their part, Fleming's lawyers say Leeper's failure was grossly negligent, and blame for it is shared by everyone involved in the case.

"What I truly believe is that everyone on that side is at fault," said Taylor Koss, the former Brooklyn prosecutor and Leeper protégé. "If they had stood up to their ethical obligations, all of this information would've been sent over and all of this could've been avoided."