“They’re sharing data across their networks, and this introduces just a more vast and fast dissemination of personal information than existed 10 years ago or before that,” Ms. Borchetta said. “These technologies represent great advancements in law enforcement but they also create new privacy concerns.”

Eugene O’Donnell, a former city police officer who now teaches at John Jay College, said the information contained in arrest reports is indispensable to investigators because it can help them track patterns, determine affiliations and examine particular crime spikes.

“It’s a treasure trove of information for investigators, whether you’re talking about street crime, terrorism or more sophisticated investigations,” said Professor O’Donnell, who was also a prosecutor in Brooklyn and Queens. “It’s not something you want to put out of your reach.”

Even though a sealed case did not result in a conviction, he said, that does not always mean a person did not commit a crime or other egregious act.

“If you want to hire someone for a position of trust, do you want to be blind to that or see what was on file?” he said. “There are very clear cases where someone got away with a very serious crime for whatever reason.”

Narrow exceptions in the sealing statutes allow access to someone’s sealed case records for prosecutors, parole and corrections agencies, gun licensing authorities, and employers that hire peace officers and police officers. For instance, prosecutors may see the sealed records of someone to whom they are considering offering a deal to dismiss a subsequent case if the person stays out of trouble for a certain period of time. In another example, police departments are permitted to access the sealed arrest records of people who apply to become officers.

But the process for the police to obtain a court order for individuals’ records can be burdensome, Professor O’Donnell said, and the lawsuit could spur the Legislature to amend the statutes, which lawmakers expanded last year to include nonviolent criminal convictions more than 10 years old. Or, he said, it might prompt a streamlining of the process to obtain court approval for sealed records, much as the process for getting warrants has been simplified.