ABOUT NEW YORK
A Switch Is Flipped, and Justice Listens In

By JIM DWYER
On Christmas Day 2005, Erik Crespo was given a small red MP3 player as a gift. That night, he got on an elevator in the Highbridge section of the Bronx and shot a man in the face.

There was no mystery about the shooting: Surveillance cameras in the building captured much of it on tape, and Mr. Crespo, 17, was squarely implicated.

What followed, though, was an object lesson in just how ungovernable history has become now that digital technology has made it possible for almost any human exchange to be easily, and cheaply, recorded.

Six days later, Detective Christopher Perino, from the 44th Precinct, caught up with Mr. Crespo and took him into an interrogation room. Mr. Crespo offered his explanation for the shooting: He was being threatened. Detective Perino said that made sense, but he still wanted to pin down a few details, like what had happened to the gun. Also, he would need a written statement from Mr. Crespo.

�And our conversation right now does not exist, you following me?� Detective Perino said.

�Yes,� Mr. Crespo said.

�But in order for our conversation to exist, in order for your words to be on the record, I have to read you your rights,� the detective continued.

In fact, rights or no rights, the conversation did exist. At some point, Mr. Crespo had reached into a pocket. His brand-new MP3 player, the one he had gotten a week earlier for Christmas, had a recording feature. Mr. Crespo secretly switched it on. For the next 16 months, Detective Perino had no idea that 16,000 words of a conversation he had declared nonexistent had been captured on the little red MP3 device.

Then Mr. Crespo went on trial. Detective Perino � the last and probably least necessary prosecution witness, given all the other evidence that implicated Mr. Crespo � denied that his questioning of Mr. Crespo had ever taken place.

Over and over, he insisted under cross-examination by Mr. Crespo�s lawyer, Mark S. DeMarco, that he had not asked Mr. Crespo about the gun, or urged him to tell his story. �I never interrogated your client,� the detective said under oath.

The defense lawyer produced transcripts of the session, and a CD of the recording. A recess was called. The prosecutors, who before the trial had offered Mr. Crespo a plea bargain with a 15-year sentence, came back to court a few hours later and offered a sentence of seven years.

Mr. Crespo took the deal. On Thursday, Detective Perino, who has spent 19 years in the Police Department, was indicted on 12 felony counts of perjury. If he is found guilty, he will lose his job and possibly his pension. And if it is proved that he did not tell the truth on the witness stand, it will be one of the rare occasions in which a lie by a police officer helped a criminal defendant � in this instance, a man whose role in the shooting was never in doubt.

Nearly 20 years ago, the introduction of DNA testing transformed the investigation of crimes that involved human tissue � blood, semen, saliva, skin � by introducing a level of precision that human memory and witness could never provide.

Now, digital technology has brought a second wave of transformation, offering new precision about what people did or said, regardless of whether they spilled blood in the process, or how the actions are portrayed in news accounts or in official statements.

So one set of surveillance cameras showed Mr. Crespo getting on an elevator and captured the shooting that followed, leaving little doubt about his actions. Another set showed two auxiliary police officers in Greenwich Village being gunned down in March. And small digital video cameras carried by members of the public showed that many people arrested during the 2004 Republican National Convention had not been breaking the law or doing anything that resembled what they were charged with; a year earlier, cameras showed that thousands and thousands of people were kept away from a war protest by barricades.

Digital technology has created free-range history.

Yet in one area, the Police Department has stoutly resisted the use of this new machinery: the questioning of suspects, which can go on for hours before the cameras start rolling. In many police departments across the country, all of the questioning is recorded.

Though Detective Perino now stands accused of lying about how he interrogated Erik Crespo, there actually seems to be little in the encounter for him to be embarrassed about. He simply might not have shaken the habit of owning history.