The New York Police Department has skirted rules governing how it does surveillance by letting investigations continue past court-mandated deadlines and not spelling out how it uses undercover officers and informants, the city's independent police monitor said in a report released Tuesday.

NYPD officials immediately responded by characterizing the criticisms contained in the report by Inspector General Philip Eure as more technical than substantive. They also said the department had implemented a new electronic tracking system that will notify them when authorization for surveillance has expired.

"We believe we've adhered to the spirit and the letter of the law in each instance," the NYPD's top attorney, Lawrence Byrne, said at a news conference. "We don't break the law to enforce the law."

The audit of terrorism and other probes conducted by the NYPD Intelligence Division found that it failed to renew authorization in a timely way in more than half of the cases under review. Eure's report also accused the division of failing to follow rules requiring that applications for permission to do undercover investigations "must state the particular role of the undercover in that specific investigation, so that the need for this intrusive technique can be evaluated."

The NYPD "almost never included such a fact-specific discussion in its applications, but instead repeatedly used generic, boilerplate text to seek such permission," the reported added. "Tellingly, this boilerplate text was so routine that the same typographical error had been cut and pasted into virtually every application."

The department's top intelligence official, John Miller, countered that Handschu restrictions don't prohibit the use of boilerplate language in the paperwork, and that it's sometimes needed for the sake of confidentiality.

"The fact is that detailing what an individual person's role is going to be before they're deployed, before the case takes its own direction, is a very risky venture, in terms of not just revealing that person's identity, but also by predicting what's going to happen that hasn't happened yet," Miller said.

The report comes eight months after the city agreed to settle lawsuits accusing the department of waging a covert campaign of religious profiling and illegal spying. As part of the deal, the NYPD agreed to codify civil rights and other protections required under the court-ordered Handschu decree — put in place in response to surveillance used against war protesters in the 1960s and '70s — that ban investigations based on race, religion or ethnicity and require use of the least intrusive investigative techniques possible.

The suits were among legal actions that followed reports by The Associated Press that revealed how city police infiltrated Muslim student groups, put informants in mosques and otherwise spied on Muslims as part of a broad effort to prevent terrorist attacks.

A footnote in the report said of the case files reviewed, 95 percent involved Muslims or other people associated with Islam, "although NYPD does not use such categorizations in its approval documents."

Donna Lieberman, executive director of the New York Civil Liberties Union, called the findings "more evidence that the NYPD's surveillance of American Muslims was highly irregular, operated in a black box and violated even the weaker rules that existed before our proposed settlement."