Four years after the banking system nearly collapsed from reckless mortgage lending, federal prosecutors have stayed on the sidelines, even as judges around the country are pointing fingers at possible wrongdoing.

The federal government, as has been widely noted, has pressed few criminal cases against major lenders or senior executives for the events that led to the meltdown of 2007. Finding hard evidence has proved difficult, the Justice Department has said.

The government also hasn't brought any prosecutions for dubious foreclosure practices deployed since 2007 by big banks and other mortgage-servicing companies.

But this part of the financial system, a Reuters examination shows, is filled with potential leads:

Foreclosure-related case files in just one New York federal bankruptcy court, for example, hold at least a dozen mortgage documents known as promissory notes bearing evidence of recently forged signatures and illegal alterations, according to a judge's rulings and records reviewed by Reuters. Similarly altered notes have appeared in courts around the country.

Banks in the past two years have foreclosed on the houses of thousands of active-duty U.S. soldiers who are legally eligible to have foreclosures halted. Refusing to grant foreclosure stays is a misdemeanor under federal law.

The U.S. Treasury confirmed in November that it is conducting a civil investigation of 4,500 such foreclosures. Attorneys representing service members estimate banks have foreclosed on up to 30,000 military personnel in potential violation of the law.

In Alabama, a federal bankruptcy judge ruled last month that Wells Fargo & Co. had filed at least 630 sworn affidavits containing false "facts," including claims that homeowners were in arrears for amounts not yet due.

Wells Fargo "took the law into its own hands" and disregarded laws banning perjury, Judge Margaret A. Mahoney declared.

And in thousands of cases, documents required to transfer ownership of mortgages have been falsified. Lacking originals needed to foreclose, mortgage servicers drew up new ones, falsely signed by their own staff as employees of the original lenders - many of which no longer exist.

But the mortgage-foreclosure mess has yet to yield any federal prosecution against the big banks that are the major servicers of home loans.

UNPRECEDENTED FRAUD

Reuters has identified one pending federal criminal investigation into suspected improper foreclosure procedures. That inquiry has been under way since 2009.

The investigation focuses on a defunct subsidiary of Jacksonville, Florida-based Lender Processing Services, the nation's largest subcontractor of mortgage servicing duties for banks.

People close to the investigation said indictments may come as early as the end of this month. Nationwide press reports had showed photos of what appeared to be obviously forged signatures on foreclosure affidavits.

The Justice Department doesn't disclose pending investigations, making it impossible to say if other criminal inquiries are underway. Officials in state attorneys' general offices and lawyers in foreclosure cases say they have seen no signs of any other federal criminal investigation.

"I think it's difficult to find a fraud of this size on the U.S. court system in U.S. history," said Raymond Brescia, a visiting professor at Yale Law School who has written articles analyzing the role of courts in the financial crisis. "I can't think of one where you have literally tens of thousands of fraudulent documents filed in tens of thousands of cases."

Spokesmen for the five largest servicers - Bank of America Corp., Wells Fargo & Co., JP Morgan Chase & Co, Citigroup Inc., and Ally Financial Group - declined to comment about the possibility of widespread fraud for this article.

Paul Leonard, spokesman for the Housing Policy Council, whose membership includes those banks, said any faults in foreclosure cases are being addressed under a civil settlement earlier this year with federal regulators.

FALSE STATEMENTS

Justice Department and Federal Bureau of Investigation officials say they have brought mortgage-fraud criminal cases through their "Operation Stolen Dreams." None, however, were against big banks. All targeted small-scale operators who allegedly defrauded banks with forged mortgage applications or took advantage of homeowners by falsely promising arrangements to get them out of default and then pocketing their money.

Justice Department spokeswoman Adora Andy declined to comment on the absence of prosecutions for foreclosure practices by big banks. She said in a statement: "The Department of Justice has been and will continue to aggressively investigate financial fraud wherever it occurs, including at all levels of the mortgage industry and, when we find evidence of a crime, we will not hesitate to pursue it."

Some judges have accused banks of falsely stating in court that they are working on loan modifications for homeowners in default.

In a November 30 court hearing, not previously reported, a federal bankruptcy judge in New York accused Bank of America of falsely telling courts and the public that it was working to renegotiate loans.

"Bank of America issues constant press releases about how it is responsive to their borrowers on these issues. They are not, period," said Judge Robert Drain, in a case involving homeowner Richard Tomasulo, a pharmacist from Crompond, New York. Drain said Bank of America had been telling the court since January that it was working to modify Tomasulo's mortgage, but hadn't done so.

"Whoever is in charge of this program and their supervisor, who should be following it, should be fired" because "they are frankly incompetent."

Bank of America spokeswoman Jumana Bauwens said the bank has completed "nearly one million" modifications since 2008. The U.S. Treasury this year suspended loan modification incentive payments to the bank because it was "seriously deficient" in responding to requests for modifications.

CHEATERS AND LIARS

Foreclosure fraud came to light in September 2010, with evidence that employees of Ally Financial Corp. had committed "robo-signing," in which low-level workers signed and swore to the facts in thousands of affidavits they hadn't read or checked.

The affidavits were notarized outside the signers' presence, in apparent violation of state and federal criminal laws.

Since then, mounting evidence of possible foreclosure fraud has convinced judges and state regulators that servicers have harmed homeowners and the investors who bought mortgage-backed securities.

A unit of the Justice Department that oversees bankruptcy court cases, the U.S. Trustees Program, said in its 2010 annual report that there were "pervasive and longstanding problems regarding mortgage loan servicing," which "are not merely 'technical' but cause real harm to homeowners in bankruptcy."

Banks, the Trustees Program says, have falsified affidavits by claiming homeowners owe fees for services never rendered and by overstating how much owners are behind on payments.

Former federal prosecutor Daniel Richman, a professor of criminal law at Columbia University Law School, says a central question is who prosecutors would target in criminal investigations. Richman said it would be easy but not worthwhile to charge large numbers of rank-and-file workers who, directed by supervisors, falsely churned out affidavits.

He said criminal investigations would be warranted, but harder to bring, "if there are particular individuals who lie at the heart of this conduct in a very significant way."

In October 2010, members of Congress pressed the Justice Department to investigate. Attorney General Eric Holder said investigations were best left to the states, with help from the Justice Department.

The Office of the Comptroller of the Currency, the top bank regulator, quickly negotiated settlements with the 14 largest servicers, requiring changes in practices and "remediation" for harmed homeowners. That settlement allows the banks to choose their own contractors to determine who was harmed and by how much.

Lawmakers and homeowner advocates have criticized the arrangement, contending that it will let the banks avoid making all wronged homeowners whole, because the contractors are paid by and answer to the banks.

Since then, the department's civil division has worked with a shaky coalition of all 50 states, which have been seeking a civil settlement with five banks that are the largest loan servicers. The negotiations center on requiring them to pay $20 billion or more in penalties, only some of which would go to compensate wronged homeowners.

STATES TAKE ACTION

Federal law enforcement has been noticeably absent, even in areas hardest hit by the crisis, such as Las Vegas.

In 2010 the FBI's Las Vegas office shut down its mortgage fraud task force, which had focused on small-scale swindlers.

Tim Gallagher, chief of the FBI's financial crimes section, said that the Las Vegas office had asked to transfer agents to other duties.

Impatient with the lack of federal prosecution, states including New York, Massachusetts, Delaware and California have launched their own investigations of the banks.

In November, it became the first state to file criminal charges. The state attorney general obtained a 606-count indictment against two California-based executives of Lender Processing Services.

It accuses the executives of paying Nevada notaries to forge the pair's signatures and falsely notarize them on notices of default, documents Nevada requires in foreclosure actions. State officials said more indictments are expected.

In an interview, John Kelleher, Nevada's chief deputy attorney general, said the investigation began in response to citizen complaints.

"We were concerned and then shocked at the sheer number of fraudulent documents we were finding that had been filed with the county recorder," Kelleher said.

Investigators found "tens of thousands" of false records filed on behalf of big mortgage servicers, he said.

The two executives have pleaded not guilty. In a press release, the company said: "LPS acknowledges the signing procedures on some of these documents were flawed; however, the company also believes these documents were properly authorized and their recording did not result in a wrongful foreclosure."

BACK HOME IN NEW YORK

The U.S. Attorney's Office in Manhattan is the federal prosecutors' office that traditionally has filed the most cases against top banks and financiers. But it hasn't brought any foreclosure-related criminal cases involving Wall Street's biggest financial houses or the law firms that represent them.

To date the only step it has taken publicly was an October 2011 civil settlement with New York State's largest foreclosure law firm.

The Steven J. Baum P.C. law firm, based near Buffalo, New York, in recent years filed approximately 40 per cent of all foreclosures in New York State, on behalf of banks and other mortgage servicers. Court records show that the firm angered state court judges for alleged false statements and filing suspect documents.

Arthur Schack, a state court judge in Brooklyn, in a 2010 ruling said that pleadings by the Baum firm on behalf of HSBC Bank, a unit of London-based HSBC Holdings, in a foreclosure case were "so incredible, outrageous, ludicrous and disingenuous that they should have been authorized by the late Rod Serling, creator of the famous science-fiction television series, The Twilight Zone."

Another state judge that year imposed $5,000 in sanctions and ordered the firm to pay $14,500 in attorneys' fees, ruling that "misrepresentation of the material statements here was outrageous."

But the U.S. Attorney's office in Manhattan filed no criminal charges against the Baum firm. Instead, it signed a settlement with Baum ending an inquiry "relating to foreclosure practices." The agreement made no allegations of wrongdoing, but required the firm to improve its foreclosure practices.

Baum agreed to pay a $2 million civil penalty, but didn't admit wrongdoing.

The law firm said it would shut down after New York Times columnist Joe Nocera in November published photographs of a 2010 Baum firm Halloween party in which employees dressed up as homeless people. Another showed part of Baum's office decorated to look like a row of foreclosed houses.

"The settlement between the Manhattan U.S. Attorney's Office and the Steven J. Baum Law Firm resulted in immediate and comprehensive reforms of the firm's business practices," said Ellen Davis, spokeswoman for the Manhattan U.S. Attorney's office.

Earl Wells III, a spokesman for Baum, said the lawyer wouldn't comment because "he's laying low right now."

An HSBC spokesman said: "We are working closely with the regulators to address any matters raised regarding" the bank's foreclosure practices.

BROKEN PROMISES

The most serious potential foreclosure violations involve falsified mortgage promissory notes, the documents homeowners sign vowing to repay mortgage loans. Courts uniformly have ruled that unless a creditor legally owns the promissory note, it has no legal right to foreclose. For each mortgage there is only one promissory note.

Bankruptcy court records reviewed by Reuters show that at least a dozen radically different documents purporting to be the authentic promissory note have turned up in foreclosure cases involving six different properties in the federal bankruptcy court for the Southern District of New York.

In one, Wells Fargo is battling to foreclose on the Bronx home of Tindala Mims, a single mother who works as an ambulance driver. In September 2010, Wells Fargo filed a promissory note bearing a signed stamp showing that the note belonged to defunct Washington Mutual Bank, not Wells Fargo. The judge threw out the case.

In a second attempt, the court was given a different version of the note. But inspection showed physical alterations. A variety of marks on the original were missing or seemed obviously altered on the second. And the second version had a stamped endorsement, missing on the first, that appeared to give Wells Fargo the right to foreclose.

The judge threw out the second attempt too. Wells Fargo is trying a third time. It declined to comment on the case.

Linda Tirelli, Mims' lawyer, in October sued Wells Fargo, alleging "fabrication of documents."

"It seems to me that Washington is deathly afraid of the banking industry," Tirelli said. "If you're talking about filing false documents and filing false notarizations, do you really think that the U.S. Attorney would find it too difficult to prosecute?"

The office of Attorney Preet Bharara in Manhattan has routinely brought charges involving forgery and filing false documents against smaller targets.

In April, the FBI arrested seven employees of the USA Beauty School in Manhattan. Bharara's office alleged that the seven suspects had forged documents such as high school diplomas, attendance records and applications for financial aid for students taking cosmetology classes.

In August, Bharara's office filed felony charges against a sports-memorabilia company's CEO, accusing him of auctioning jerseys falsely advertised as "game used" by Major League Baseball players.

In a press conference, a U.S. Postal Inspection Service official said prosecution was important because "victims felt that they had a piece of history only to be defrauded and left with a feeling of heartbreak."

Given the record of Bharara's office, and those of his fellow U.S. Attorneys around the country, to aggressively pursue violations both big and small, the absence of cases involving the foreclosure fiasco seems to stand out.

"Why there hasn't been more robust prosecution is a mystery," said Brescia, the visiting professor at Yale.

U.S. Attorney General Eric Holder and Lanny Breuer, head of the Justice Department's criminal division, were partners for years at a Washington law firm that represented a Who's Who of big banks and other companies at the center of alleged foreclosure fraud, a Reuters inquiry shows.

The firm, Covington & Burling, is one of Washington's biggest white shoe law firms. Law professors and other federal ethics experts said that federal conflict of interest rules required Holder and Breuer to recuse themselves from any Justice Department decisions relating to law firm clients they personally had done work for.

Both the Justice Department and Covington declined to say if either official had personally worked on matters for the big mortgage industry clients. Justice Department spokeswoman Tracy Schmaler said Holder and Breuer had complied fully with conflict of interest regulations, but she declined to say if they had recused themselves from any matters related to the former clients.

Reuters reported in December that under Holder and Breuer, the Justice Department hasn't brought any criminal cases against big banks or other companies involved in mortgage servicing, even though copious evidence has surfaced of apparent criminal violations in foreclosure cases.

The evidence, including records from federal and state courts and local clerks' offices around the country, shows widespread forgery, perjury, obstruction of justice, and illegal foreclosures on the homes of thousands of active-duty military personnel.

In recent weeks the Justice Department has come under renewed pressure from members of Congress, state and local officials and homeowners' lawyers to open a wide-ranging criminal investigation of mortgage servicers, the biggest of which have been Covington clients. So far Justice officials haven't responded publicly to any of the requests.

While Holder and Breuer were partners at Covington, the firm's clients included the four largest U.S. banks — Bank of America, Citigroup, JP Morgan Chase and Wells Fargo & Co — as well as at least one other bank that is among the 10 largest mortgage servicers.

DEFENDER OF FREDDIE

Servicers perform routine mortgage maintenance tasks, including filing foreclosures, on behalf of mortgage owners, usually groups of investors who bought mortgage-backed securities.

Covington represented Freddie Mac, one of the nation's biggest issuers of mortgage backed securities, in enforcement investigations by federal financial regulators.

A particular concern by those pressing for an investigation is Covington's involvement with Virginia-based MERS Corp, which runs a vast computerized registry of mortgages. Little known before the mortgage crisis hit, MERS, which stands for Mortgage Electronic Registration Systems, has been at the center of complaints about false or erroneous mortgage documents.

Court records show that Covington, in the late 1990s, provided legal opinion letters needed to create MERS on behalf of Fannie Mae, Freddie Mac, Bank of America, JP Morgan Chase and several other large banks. It was meant to speed up registration and transfers of mortgages. By 2010, MERS claimed to own about half of all mortgages in the U.S. — roughly 60 million loans.

But evidence in numerous state and federal court cases around the country has shown that MERS authorized thousands of bank employees to sign their names as MERS officials. The banks allegedly drew up fake mortgage assignments, making it appear falsely that they had standing to file foreclosures, and then had their own employees sign the documents as MERS "vice presidents" or "assistant secretaries."

Covington in 2004 also wrote a crucial opinion letter commissioned by MERS, providing legal justification for its electronic registry. MERS spokeswoman Karmela Lejarde declined to comment on Covington legal work done for MERS.

It isn't known to what extent if any Covington has continued to represent the banks and other mortgage firms since Holder and Breuer left. Covington declined to respond to questions from Reuters. A Covington spokeswoman said the firm had no comment.

Several lawyers for homeowners have said that even if Holder and Breuer haven't violated any ethics rules, their ties to Covington create an impression of bias toward the firms' clients, especially in the absence of any prosecutions by the Justice Department.

O. Max Gardner III, a lawyer who trains other attorneys to represent homeowners in bankruptcy court foreclosure actions, said he attributes the Justice Department's reluctance to prosecute the banks or their executives to the Obama White House's view that it might harm the economy.

But he said that the background of Holder and Breuer at Covington — and their failure to act on foreclosure fraud or publicly recuse themselves — "doesn't pass the smell test."

Federal ethics regulations generally require new government officials to recuse themselves for one year from involvement in matters involving clients they personally had represented at their former law firms.

President Obama imposed additional restrictions on appointees that essentially extended the ban to two years. For Holder, that ban would have expired in February 2011, and in April for Breuer. Rules also require officials to avoid creating the appearance of a conflict.

Schmaler, the Justice Department spokeswoman, said in an e-mail that "The Attorney General and Assistant Attorney General Breuer have conformed with all financial, legal and ethical obligations under law as well as additional ethical standards set by the Obama Administration."

She said they "routinely consult" the department's ethics officials for guidance. Without offering specifics, Schmaler said they "have recused themselves from matters as required by the law."

Senior government officials often move to big Washington law firms, and lawyers from those firms often move into government posts. But records show that in recent years the traffic between the Justice Department and Covington & Burling has been particularly heavy. In 2010, Holder's deputy chief of staff, John Garland, returned to Covington, as did Steven Fagell, who was Breuer's deputy chief of staff in the criminal division.

The firm has on its web site a page listing its attorneys who are former federal government officials. Covington lists 22 from the Justice Department, and 12 from U.S. Attorneys offices, the Justice Department's local federal prosecutors' offices around the country.

As Reuters reported in 2011, public records show large numbers of mortgage promissory notes with apparently forged endorsements that were submitted as evidence to courts.

There also is evidence of almost routine manufacturing of false mortgage assignments, documents that transfer ownership of mortgages between banks or to groups of investors. In foreclosure actions in courts mortgage assignments are required to show that a bank has the legal right to foreclose.

In an interview in late 2011, Raymond Brescia, a visiting professor at Yale Law School who has written about foreclosure practices said, "I think it's difficult to find a fraud of this size on the U.S. court system in U.S. history."

Holder has resisted calls for a criminal investigation since October 2010, when evidence of widespread "robo-signing" first surfaced. That involved mortgage servicer employees falsely signing and swearing to massive numbers of affidavits and other foreclosure documents that they had never read or checked for accuracy.

Recent calls for a wide-ranging criminal investigation of the mortgage servicing industry have come from members of Congress, including Senator Maria Cantwell, D-Wash., state officials, and county clerks. In recent months clerks from around the country have examined mortgage and foreclosure records filed with them and reported finding high percentages of apparently fraudulent documents.

On Wednesday, John O'Brien Jr., register of deeds in Salem, Mass., announced that he had sent 31,897 allegedly fraudulent foreclosure-related documents to Holder. O'Brien said he asked for a criminal investigation of servicers and their law firms that had filed the documents because they "show a pattern of fraud," forgery and false notarizations.