The Inspector General of New Orleans has accused the NOPD of under-reporting robberies in the city over a three year period beginning in June 2010.

Ed Quatrevaux says his office selected that crime category for a study because in 2012, robbery in New Orleans was 46% lower than 24 other U.S. cities with the highest crime rates.

Among other things, Quatrevaux says his auditors found that the NOPD misclassified 37% of robberies under the heading "miscellaneous" offenses. He also says the department did not report known robberies when the victim refused to cooperate.

In May, the IG accused the department of under reporting sexual assaults.  He says the most recent findings "suggest that problems with reporting accuracy are across-the-board.

Before he retired from the department earlier this month, former Superintendent Ronal Serpas challenged the IG's most recent report terming the NOPD's error rate "well within the norm."

Quatrevaux says his office will conduct an inspection of all items classified as "miscellaneous" next year.