A nine-month internal review of the New Orleans Police Department’s embattled Sex Crimes Unit has determined that the detective squad’s troubles weren’t nearly as horrifying as Inspector General Ed Quatrevaux described last year in a blistering report on the output of five detectives.

Nor did the documented failures of those detectives or their supervisors rise to a criminal level, NOPD Superintendent Michael Harrison said Tuesday.

Still, many cases weren’t thoroughly investigated by the detectives that Quatrevaux’s office targeted, a group that makes up about a third of the NOPD’s Special Victims Section, the review found.

“Right now, we have not found any criminal violations, but a number of administrative violations that we’re dealing with,” Harrison said. “It’s going to be cases of neglect of duty, cases of supervisory neglect, cases of improper documentation — things of that nature. Some of them are multiple offenses.”

The review by the NOPD’s Public Integrity Bureau unearthed a significant portion of the paperwork that the IG’s Office found lacking in hundreds of sex-crime case files. The digging by PIB nevertheless revealed massive administrative dysfunction in the section, along with several perfunctory rape investigations — just not in the volume initially feared.

In the wake of the IG report, Mayor Mitch Landrieu ordered a task force led by 2nd District Commander Paul Noel to reinvestigate some 271 cases from 2011 to 2013 that Quatrevaux’s office flagged as lacking even a basic follow-up report. The task force then added dozens of other rape cases to the list, mostly from last year.

Noel said his task force has completed investigations into 54 sex crime and child abuse cases. So far, six have reached District Attorney Leon Cannizzaro’s office, where they remain under review, DA spokesman Christopher Bowman said.

Harrison announced the findings of the PIB review at a news conference Tuesday at Gallier Hall in which Landrieu endorsed sweeping reforms to sex crime investigations, as proposed by an advisory committee made up of advocates, police, prosecutors and city officials.

“For too long, quite frankly, we have done a poor job in this city in responding to sexual assault,” the mayor said, admitting that an earlier stab at reforms failed to “pull the problem out by the root.”

According to a report released Tuesday by the advisory committee, the changes already instituted include:

Adding two new detectives and a supervisor to the Sex Crimes and Child Abuse units.

Removing those detectives from the rotation for special events duty, authorizing overtime for investigations and getting them better equipment.

Increased training and tightened supervision of detectives.

Hiring a third DNA analyst at the state Crime Lab to speed up processing of rape kits and requiring quick reporting to reduce a backlog that reached 400 last year.

Moving the Sex Crimes Unit to the victim-friendly Family Justice Center.

Among further slated changes are reduced caseloads for Sex Crimes and Child Abuse detectives; new “multidisciplinary teams” to review sex crime cases; a 5 percent pay boost for detectives starting next year; private lab testing for a backlog of 180 rape kits; and the hiring of three social workers as victim witness coordinators.

“I have never been as proud of anything in my career,” said Tania Tetlow, a Tulane law professor and former federal prosecutor who chaired the committee. “This report is really a report of things already accomplished, already agreed to. I have never seen any level of government work this quickly or treat something as high a priority as this.”

State Sen. J.P. Morrell praised the mayor for admitting the problem, saying: “The apathy of law enforcement across this state is a cancer. The city of New Orleans, what they’re doing is invasive surgery.”

Last week, Harrison reported a 55 percent rise in rape reports in New Orleans for the first half of the year, saying it largely results from victims growing more comfortable reporting rape, not a spike in assaults. Officials said they expect rape reports to keep rising.

NOPD spokesman Tyler Gamble said little has changed in how police categorize such reports, but that the department has changed the way it classifies many calls for service that had appeared in Quatrevaux’s report to signal a reported sex crime when there was none.

The IG report found 840 calls for service assigned to the five detectives had been deemed “miscellaneous,” with no paperwork at all. But the NOPD’s review determined that the vast bulk — 760, according to Harrison — were checks on registered sex offenders. Police now record those checks differently, Gamble said.

The IG report went deeper, homing in on detectives Akron Davis, Vernon Haynes, Merrell Merricks, Derrick Williams and Damita Williams, after an earlier audit flagged potential problems with some of the their investigations.

The more in-depth November report found the detectives had failed to document any real work in most cases assigned to them for the three years ending Dec. 31, 2013. Of the 450 combined sex crime cases for which they penned cursory initial reports, 60 percent lacked supplemental reports documenting an investigation, the report stated.

Merricks and Derrick Williams also were accused of ginning up reports that they backdated on the same day in 2013 after the IG’s Office asked for missing reports, said First Assistant Inspector General Howard Schwartz, who led the IG investigation.

Davis had been assigned to the Child Abuse Unit. The other four were in the Sex Crimes Unit, which usually has eight or nine detectives.

“These revelations suggest an indifference to our citizens that won’t be tolerated,” Quatrevaux said at the time.

Landrieu at the time called the IG’s findings “a disgrace,” and Harrison said criminal charges could follow. He quickly reassigned the five detectives, then sat them at desks pending the PIB review. He also installed new leadership over the section.

Even without paperwork, the five detectives shipped 105 cases to prosecutors and the DA’s Office accepted 74 of them, doing much of the legwork on its own, the IG found,

But the NOPD’s review turned up many supplemental reports that Quatrevaux’s office never saw, officials said Tuesday. Some turned up in a database, others in DA’s Office files. Still others sat on the detectives’ own jump drives, NOPD Deputy Chief Arlinda Westbrook said.

“Some of that is on us, because we didn’t give them what we had or tell them where it was,” Harrison said. “We own up to that.”

Schwartz noted that the IG report focused on missing paperwork in hundreds of cases. That critique remains valid, he said.

“We started out, we were going to do a review of the investigations. We couldn’t get to that point. We couldn’t even find the most basic documentation,” Schwartz said. “Give PIB credit. It took them months to put all this together. They found some in a cabinet somewhere.”

Schwartz said the IG report “pointed out a systemwide error, a breakdown. It’s vital that proper documentation, especially with sex crimes, is available for review.”

Donovan Livaccari, spokesman for the local Fraternal Order of Police, said he understood that PIB had little trouble finding some of the missing reports in the Sex Crimes Unit office.

“There were documents that were not discovered in the course of the IG’s investigation, and I don’t know whose fault that was,” Livaccari said. “I would hope that (the five detectives) would be returned to full duty first and foremost, and then we can move on with examining any sustained violations and dealing with those on an individual basis.”

Follow John Simerman on Twitter, @johnsimerman.