Boston police were caught red-handed earlier this month when, during a casual Internet search, alt-weekly Dig Boston uncovered sensitive documents illustrating the city government’s surveillance during its inaugural Boston Calling Music Festival, in which cameras with facial-recognition technology analyzed concertgoer information, including their height, clothing, and skin color. But putting privacy issues aside, the technology’s purpose, of logging citizen information in case they later end up guilty of a crime, will likely fall short.

Dig’s reporters discovered the documents while searching the web for keywords related to surveillance in Boston. What they found was a collection of documents regarding the police department’s involvement with IBM — who worked as an outside contractor — in using over 10 cameras to record data ranging from traffic congestion to social media analytics, and to screen people for anatomical data, including skin color, head and torso color; and other features like whether they have eyeglasses. The documents included memos from IBM employees speaking about using IBM’s “Face Capture” technology on “every person” at the concert.

Although Boston Police initially denied involvement with the project — even though the documents included a picture of IBM employees instructing officers how to use the system — the mayor’s press secretary outed them in a press release, saying:

The City of Boston engaged in a pilot program with IBM, testing situational awareness software for two events hosted on City Hall Plaza: Boston Callin in May 2013, and Boston Calling in September 2013. The purpose of the pilot was to evaluate software that could make it easier for the City to host large, public events, looking at challenges such as permitting, basic services, crowd and traffic management, public safety, and citizen engagement through social media and other channels.

Although there are so many privacy issues to consider (Dig gets into these in parts one and two of its report), Face Capture may still fall short of its intended purpose. After all, facial recognition technology failed to match video footage of the Boston bombers Tamerlan and Dzhokhar Tsarnaev to their driver’s license photos, or even Tamerlan to his information in an FBI database, according to PBS.

Often, this happens because facial recognition cameras photograph peoples’ faces under different lighting, at different angles, or because they have different facial hair or expressions. In one of IBM’s PowerPoints showing how facial recognition analytics looks, a man without eyeglasses, but with sunken eyes, is believed to be wearing glasses — the computer was 99 percent sure. So, if police departments around the country wanted to use the technology in music festivals where drug use is rampant, such as electronic dance music festivals, it may not be as effective as some would hope in capturing people selling drugs. What’s more, festivalgoers frequently wear costumes or masks, or paint their faces.

Boston was one of 33 cities around the world that received grants for IBM’s “Smarter Cities Challenge,” worth about $400,000, in 2012. “The cities that have been selected are different, but they had one clear similarity: The strong personal commitment by the city’s leadership to put in place the changes needed to help the city make smarter decisions,” said Stanley Litow, IBM’s vice president of Corporate Citizenship & Corporate Affairs, in a 2012 press release. How smart we really want our cities, however, is another question.