Issuing summonses for quality of life crimes, or those that fall within “broken windows”-style policing, doesn’t necessarily lead to a drop in felony crimes, according to a Department of Investigation report released Wednesday.

Police Commissioner Bill Bratton has extolled the benefits of “broken windows”-style policing since he first took over the department in the 1990s. The theory purports that by focusing on nonviolent crimes, like drinking in public, police can prevent more serious crimes.

“The results of our investigation call into question some long-held assumptions about the systemic impact of certain tactics and therefore provide a starting point for the NYPD to more fully employ statistical analysis to evaluate these tactics,” DOI Commissioner Mark Peters said in a statement, adding that this is the “first ever independent, data-driven investigation” of its kind.

The data comes as Mayor Bill de Blasio — supported by the NYPD — signed into law last week a series of reforms aimed at reducing arrests for low-level offenses, such as public urination or littering.

“The Inspector General’s report and its basic assumptions and so-called statistical methodology are deeply flawed,” a representative for the NYPD said in an email on Wednesday. “The report fails to acknowledge what all New York City residents know: that every community in the city is safer and has a better quality of life due in large part to the extensive quality of life enforcement efforts and proactive policing that was implemented in 1994 by the New York City Police Department.”

The representative said the report focuses on five years, which is a “narrow” time period. The NYPD plans to release a more detailed response within the next 90 days.

The DOI’s study looked at more than 1.8 million quality of life summonses and more than 650,000 related misdemeanor arrests from 2010 to 2015, among other statistics.

During that time, there was a “dramatic decline” in enforcement of these mostly nonviolent offenses, according to the report. And, for the most part, felony crime decreased right alongside it.

“This does not demonstrate that issuance of quality-of-life summonses has no impact on felony crime — that conclusion would require additional data and analysis,” according to the report. “However, it is clear that broad generalizations about quality-of-life summonses as a panacea are not supported by empirical evidence derived from [Office of the Inspector General for the NYPD’s] analysis.”

The report also found that these quality-of-life crimes aren’t enforced equally throughout the city. In fact, in 2015 these crimes seemed to be disproportionally enforced in precincts where there is a high proportion of black and Hispanic residents as well as housing projects.

The report doesn’t necessarily challenge the need for such summonses and misdemeanor arrests, but suggests that the data should give the department cause, encouraging the NYPD to “consider both short-term and long-term conditions” when making policing decisions.

“This Report looks solely at the question of whether quality-of-life enforcement has any measurable relationship to felony crime,” the report reads. “This Report does not speak to the use of quality-of life enforcement to maintain order, nor does it speak to any type of quality-of-life enforcement other than quality-of-life summons and misdemeanor arrest activity.”