The NYPD simply can’t police itself, the New York Civil Liberties Union says in a new report that finds serious discipline was meted out in just 1% of cases investigated by a city watchdog agency over the past two decades.

The NYCLU’s report, “COP OUT: Analyzing 20 Years of Records Proving NYPD Impunity,” reviewed 180,700 complaints filed with the Civilian Complaint Review Board and found that officers were disciplined just 4,283 times.

The investigations led to serious penalties like loss of vacation days, suspensions, probation or termination in just 1,530 cases, or 1% of the time. The NYCLU did not consider training letters of instruction, which are admonishment letters placed in an officer’s file, to be serious discipline.

The NYCLU report, released Tuesday, covers CCRB investigations from the start of 2000 to those completed by April of 2021.

It noted that when the CCRB did substantiate a complaint — something it did 12,980 times — the NYPD in 74% of the cases ignored the recommended penalty and either imposed a lower penalty or none at all.

Christopher Dunn, the NYCLU’s legal director, said it’s no wonder the city concealed misconduct records for years through a state privacy law, 50-a, that was repealed last year.

“The numbers make clear that NYPD oversight and discipline is largely fiction,” Dunn said. “Now that the secret is out, the NYPD’s monopoly over discipline must end.”

The NYPD emphasized that the NYCLU analysis focused on a 20-year period during which much had changed.

“Because of improvements made by the NYPD and CCRB in the last eight years of collaboration, investigations have improved, processes have been streamlined and cooperation has increased between the two agencies ... For 2020, NYPD disciplinary cases resolved at trial had a conviction rate of 73%,” the NYPD said in a statement.

The report calls for, among other things, rescinding the police commissioner's power to make the final call in all disciplinary cases. The report also recommends police disciplinary cases be heard not in a trial room at NYPD headquarters but instead in the city tribunal where employees for other agencies face disciplinary proceedings.

“The disciplinary matrix established clear and consistent presumptive penalties for specific offenses, which can be utilized by both the NYPD and CCRB. This indicates a system that is functioning and holding police officers appropriately accountable,” the NYPD said.

Critics of the disciplinary matrix, which was unveiled in January, complain that it is not legally binding and doesn’t reduce the NYPD commissioner’s ultimate authority over how punishments are meted out for cops’ misconduct.

The NYCLU report breaks down complaints and discipline by race, noting that Black New Yorkers are six times more likely than whites to accuse police of misconduct and that Black officers were 33% more likely than white cops to be seriously disciplined.

The most complaints were filed against officers in the 75th Precinct, which covers East New York and Cypress Hills.

“It is important to note that about 90% of NYPD officers go through their entire career without a single substantiated CCRB complaint or departmental charge,” the NYPD said. “An allegation is just that, it is not evidence of misconduct.”