‘Mistakes Based on Faulty Memory’

The Police Department has pushed back against the claim that lies by officers are not punished.

J. Peter Donald, a spokesman, said the Police Department’s Internal Affairs Bureau has grown more effective in recent years at catching dishonest officers. It has, for example, expanded its integrity-testing unit in which undercover investigators pretend to be crime victims, witnesses or suspects in order to see how officers respond.

“We’re proactively rooting out people who have a problem with the truth,” he said.

Separately, the Police Department convened a panel of top officials who, since 2016, have been reviewing every case in which a judge finds that an officer’s testimony was not believable. The department’s top legal official, Lawrence Byrne, said the cases were not, in the aggregate, indicative of a systemic problem. Often, Mr. Byrne said, the police officer’s testimony was undermined by “mistakes based on faulty memory, not an intentional lie.”

Another police legal official, Ann P. Prunty, went further, saying that at times it is the judges, not the police officers, who are in error. “Sometimes you see a judge who just has a bias and thinks that an officer’s account is implausible,” said Ms. Prunty, an assistant deputy commissioner for legal matters and a former prosecutor in Manhattan. “When you look at it, it is. It’s quite plausible.”

The Police Department noted that it brings dozens of disciplinary proceedings against police officers for making a “false statement” each year. But many of those cases appear to involve internal disciplinary matters — such as falsehoods about injuries, the circumstances of car accidents or off-duty misconduct — rather than incidents in which officers lied about arrests.

“If you intentionally make a false statement as a police officer, as opposed to a mistake, you can and will be terminated for that,” Mr. Byrne said. More than 70 officers have been “fired or forced out of the department in the last five years” for perjury or false statements, Mr. Byrne said in October at a New York City Bar Association event. About 150 more were disciplined to a lesser extent for making false statements in recent years, he said.