In recent years, the integrity of the Police Department’s crime statistics has been questioned as accounts emerge by officers who say they are being pressured by their bosses to reduce the number of felony incidents reported.

The issue is particularly sensitive for Mayor Michael R. Bloomberg and his police commissioner, Raymond W. Kelly, who have overseen a significant decline in serious felony crimes throughout their tenure. As that decline has slowed — the yearly crime rate rose slightly in 2011, and is currently running 4.4 percent ahead of last year’s figure — the administration is struggling with the perception that the city is drifting back to a more violent era. Mr. Kelly created a panel in January 2011 to analyze the crime-reporting system, but the panel has not publicly issued a report yet. In addition, the Police Department conducts regular audits of police reports to detect misclassified crimes; in 2011, the error rate was 1.5 percent.

A small number of crimes the police classified as misdemeanors were eventually upgraded by prosecutors to felonies. Many inevitably resulted in plea deals to lesser charges. Nonetheless, 102 people were convicted of felony assault, despite the police’s having classified the crime as a misdemeanor, in 2011, according to data from the New York State Division of Criminal Justice Services.

It is difficult to determine why the police classify a particular case in one way and not another. Likewise, there is no conclusive evidence that police officers routinely misclassify criminal incidents, or intentionally leave out pertinent information in their paperwork in order to characterize a felony as a misdemeanor. (Misdemeanors are not counted among the seven major crime categories cited in crime statistics commonly used by law enforcement agencies like the Police Department or the Federal Bureau of Investigation.)

But in a review of more than 100 police reports from the last four months that were provided to The New York Times, there were a number of instances in which the police report seemed to portray a less serious account of a crime than the district attorney, or a victim, provided subsequently.