For years the NYPD has failed to communicate with the New York City Housing Authority about all arrests on public housing property—as well as arrests of public housing residents—despite the fact that communication of such information has been required since the late 1960s, according to a report [PDF] released this week by the Department of Investigation.

The report suggests that this "systemic failure" in communication has boosted the disproportionately high crime rates on NYCHA properties versus the rest of the city.

While about 5% of NYC residents live in public housing, 15% of homicides, 11% of rapes, and 10% of felony assaults in the city take place on the premises, the report found.

In order to conduct its investigation, the DOI reviewed more than 1,300 arrest reports pertaining to NYCHA properties or residents over the course of March 2015. The "great majority" of these arrests involved possession of small amounts of marijuana or other drugs, trespassing, and domestic violence.

Twenty seven of the 1,000+ arrests were for violent and drug-related crimes that, according to the NYPD's patrol guide, must be reported to NYCHA. The DOI found that 9 of these incidents were never reported.

Among those arrests were a resident arrested in front of the Mitchell Houses in the Bronx with a loaded pistol, a resident who allegedly threatened a neighbor with a machete, and a resident who allegedly attempted to rape the complainant inside of a NYCHA apartment.

Once NYCHA is informed of a resident arrested for an alleged violent or drug-related crime, the authority has the right to remove that individual from the premises using its discretion. A process called "Permanent Exclusion" allows NYCHA to evict individual residents who endanger "their neighbors' safety or peaceful tenancy."

Enforcement of permanent exclusion is "essentially toothless," the report charges, accusing NYCHA of letting criminal offenders remain in their housing without consequences.

In response to the report, NYCHA spokesman David Farber said in a statement to the NY Times that "NYCHA is not expanding the criteria for eviction or exclusion; rather, the authority is working with the NYPD to sharpen its policy so it moves more quickly to exclude or evict from NYCHA individuals who commit very serious offenses."

Robert Gangi, Director of the Police Reform Organizing Project, questioned the fairness of basing the dangerousness of an individual primarily off of an arrest, which precedes any proof of guilt.

"How do you determine who a 'thug' is? Is it based on the arrest?" he said. "Being arrested isn't a sure sign of that you're dangerous or predatory person. The NYPD makes so many frivolous arrests, primarily of people of color, who mainly occupy public housing. There should be a system to assess the dangerousness of an individual on a case-by-case basis."