The New York Police Department has used secretive cellphone tracking technology more than 1,000 times since 2008, according to data released Thursday by the New York Civil Liberties Union.

A cell-site simulator, also known as a Stingray, is a suitcase-sized device that can sweep up basic cellphone data from a neighborhood by tricking phones into believing it’s a cell tower, allowing it to identify unique subscriber numbers. The data are then transmitted to the police, helping them determine the location of a phone without the user even making a call or sending a text message.

Police records show the technology has helped catch suspects in kidnappings, rapes, robberies, assaults and murders. Missing people have been discovered. In some cases, no arrest was made or the phone was located but had been ditched. Officers with warrant squads, robbery squads and homicide units all used the technology, according to the records.

Federal law enforcement in September said it would be routinely required to get a search warrant before using the technology — a first effort to create a uniform legal standard for federal authorities. But the policy applies only to federal agencies within the Justice Department and not, as some privacy advocates had hoped, to state and local law enforcement whose use of the equipment has stirred particular concern and scrutiny from local judges. The NYPD would be required to get a warrant if the investigation was a joint effort with federal officials.

The NYPD said it has no written policy for use of the technology, according to the records released by the NYCLU, but general practice is to obtain a “pen register order” — a court order with a lower standard than a warrant.

Larry Byrne, the deputy commissioner of the police department’s legal bureau, said police only use the Stingray technology to retrieve cellphone numbers of calls to and from a particular phone, not the content of those communications. He said it was used only after a detective, appearing alongside an assistant district attorney, persuaded a state judge to grant the court order.

The civil liberties union urged the department to create a strict policy on use of the technology and to obtain a warrant.

“New Yorkers have very real concerns about the NYPD’s adoption of intrusive surveillance technology,” NYCLU Senior Staff Attorney Mariko Hirose said in a statement. “The NYPD should at minimum obtain warrants before using Stingrays to protect the privacy of innocent people.”

The police have already been adhering to the higher legal standard used by federal law enforcement when applying for a court order, even though state law requires the police present less, said Byrne, who added his office would put the policy in writing.

“Our practice is consistent with what the FBI and the other federal agencies now do,” he said.

The NYCLU requested documents under the Freedom of Information Law and received the first round of information that it asked for in November. Last year, the NYCLU released records showing the Erie County sheriff’s office used Stingrays 47 times in the past four years and indicating that the office obtained a pen register order only once, the agency said.

(AP)