The New Orleans Police Department misclassified dozens of forcible rapes between 2010 and 2013, violating internal policy and skewing crime data reported to the FBI, according to an audit by New Orleans Inspector General Ed Quatrevaux.

Police disputed the audit’s findings, saying the department has pushed a cultural shift to overhaul a previously “dysfunctional” rape unit and increase sexual assault reporting.

The audit, being released Wednesday, found police improperly classified nearly half of the 90 cases analyzed by Quatrevaux’s office, often by labeling them as “miscellaneous offenses” not included in statistics submitted to the national Uniform Crime Reporting Program. The allegation echoes previous criticism of the NOPD by the U.S. Department of Justice.

The audit, which covered June 2010 to May 2013, also faulted police for not completing and reviewing incident reports in a timely fashion, failing to log evidence in a few cases and violating the state’s public records law by not retaining documents to support 2010 and 2011 crime data, rendering it “unauditable.”

In an interview, Quatrevaux said he found no evidence to suggest the reporting errors had been an intentional effort to downplay the problem of sexual assaults. He said he expects next year’s statistics to reflect an increase in rapes if the department follows a series of recommendations outlined in the audit, including the reporting of “all known offenses, regardless of the victim’s willingness to cooperate.”

“Misclassification does not mean something wasn’t investigated,” Quatrevaux stressed. “This is an accounting thing, but it’s an important accounting thing. The NOPD needs (these numbers) for its analysis and operational planning, and the citizens need to have reliable data for a variety of reasons.”

“My concern is that the administrative record keeping has not been good in this area that is very important,” he added, “and it needs to be fixed.”

Police Superintendent Ronal Serpas defended the department in a nine-page response to Quatrevaux, saying he believes the NOPD “maintains precedence” in the area of crime classification. Sex-crimes detectives, he said, have been working “more closely than ever” with prosecutors, hospital workers and victims advocacy groups to improve services to sexual assault victims, leading to a significant “upsurge” in rapes reported since he took over as chief in May 2010.

“An outsider’s view should not and cannot supplant the understanding of those with decades of experience, training and knowledge of rape investigations and (Uniform Crime Reporting) classification,” Serpas wrote.

Still, the audit drew expressions of concern from several victims’ rights advocates.

Tania Tetlow, a Tulane Law School professor who heads the school’s Domestic Violence Clinic, acknowledged the city has come a long way in dealing with rape, which she said had “effectively been decriminalized” under previous administrations.

“But the report makes clear that the city has a long way to go to make sure that women are safe in the city,” Tetlow said. “There still seems to be pressure to reduce violent crime by sweeping it under the carpet instead of enforcing the law.”

Rebecca Rainey, program director at the Metropolitan Center for Women and Children, said she finds it troubling that New Orleans police were classifying as “miscellaneous offenses” cases in which women reported to the hospital with sexual-assault trauma but declined to pursue charges. She said there’s no benefit to underrepresenting the full scope of rape.

Skewed statistics, Rainey added, “have an effect when people are applying for funding and grants and trying to go in front of people and say this is a serious issue in the city.”

Quatrevaux said he intends to audit the NOPD’s rape reporting every year for the foreseeable future to ensure it is producing reliable data. “I hope that the knowledge that we’re going to do that essentially is creating some transparency and an accountability tool,” he said, “a motivation for the NOPD to take these classifications seriously.”

The Office of Inspector General said it audited the NOPD’s forcible-rape reporting because the FBI’s 2012 crime statistics indicated “forcible rape in New Orleans was 43 percent lower than in the 24 other cities with the highest crime rates.”

The audit found that 41 of 90 sexual assaults tested were misclassified — 20 as miscellaneous offenses, 7 as sexual batteries and 14 as unfounded.

Serpas, in his response, said the cases had been properly reported based on the agency’s investigation.

Perhaps the most pointed disagreement between Serpas and Quatrevaux is over whether police should report all known forcible-rape offenses, regardless of whether a victim chooses to cooperate.

Serpas said sexual assault must be “victim-centered,” citing a state law that says “the victim shall make the decision of whether or not the incident will be reported to law enforcement officials.” Even when a formal police report is not filed, he said, detectives log rape examination kits and file the cases as miscellaneous offenses, which he described as a “best practices” approach that “still provides an opportunity for victims to come forward after receiving needed support services, such as counseling.”

Quatrevaux countered that reporting a known offense does not violate the state law because the Louisiana Commission on Law Enforcement, which aggregates the state’s crime data and forwards it to the FBI, “only receives a total count.” He pointed to NOPD policy, the FBI’s UCR handbook and the Justice Department’s 2011 report, which stated that “departments must include reports of forcible rape or attempted forcible rape in their UCR data irrespective of whether the victim cooperates or an arrest is made.”

The audit also pointed to several cases in which it said the NOPD improperly classified rapes as “miscellaneous offenses” when the allegations were deemed to be unfounded. While unfounded complaints don’t affect the number of rapes reported by the UCR program, the audit said, “this information is used by the FBI to determine if the rapes are statistically within norms.”

Serpas said the department will begin reporting unfounded calls for service. But, he added, unfounded crimes are not reported publicly.

In 2011, the Department of Justice concluded in a scathing review of the NOPD that police had “systematically misclassified large numbers of possible sexual assaults, resulting in a sweeping failure to properly investigate many potential cases of rape, attempted rape and other sex crimes.”

Noting a “strikingly low” proportion of rapes to murders at the time, the DOJ review concluded the Police Department “likely had diverted many complaints of possible sexual assault from being fully investigated by classifying them as noncriminal ‘signal 21s,’ the department’s code for miscellaneous complaints.”

Racheal Hebert, executive director of the Sexual Trauma Awareness & Response Center in Baton Rouge, said rape and sexual assault remain the most unreported crimes nationwide because of the social, economic and mental-health consequences victims face when they report them to law enforcement.

“It takes a very brave and courageous person to come forward and risk being stigmatized as a ‘victim’ among their family, friends and community,” she said. “When reports of rape are not taken seriously, or when police charge perpetrators with a lesser crime, it makes victims feel dismissed and betrayed by the very system that is in place to serve and protect them.”

The audit recommended the NOPD stop using the signal for “miscellaneous offense” altogether, saying “the signal for all offenses should correlate to the type of offense per the call for service.” It noted that the federal consent decree between the city and Justice Department states that, during the first year of the court-ordered reforms of the NOPD, neither patrol officers nor detectives were permitted to code reported sexual assaults in a miscellaneous or noncriminal category without “the express written approval of the (Investigation & Support Bureau) Special Victim Section commander and the ISB Criminal Investigations Division commander.”

“Following this period,” the consent decree states, “patrol officers shall not code reported sexual assaults in a miscellaneous or noncriminal category.”

Tetlow said the NOPD has made strides toward abandoning its misguided ways of the past. But she said much work lies ahead.

“It’s very difficult sometimes to move a big ship quickly,” she said. “What has to be determined is whether this is pressure on statistics coming from the top, or whether it is the difficulty of changing the culture of the department with hundreds of officers and lots of other priorities.”

Follow Jim Mustian on Twitter, @JimMustian.