The Federal Bureau of Investigation says its facial recognition project that stores millions of mug shots and other photos is out of the pilot stage and is at "full operational capability."

The Next Generation Identification system, combined with criminal fingerprints, "will provide the nation's law enforcement community with an investigative tool that provides an image-searching capability of photographs associated with criminal identities," the FBI said in a statement Monday.

The full deployment of the program comes three months after James Comey, the bureau's director, announced that the agency was "piloting the use of mug shots, along with our fingerprint database, to see if we can find bad guys by matching pictures with mug shots."

Under the facial recognition program, law enforcement agencies will be able to cross-check images with those in other criminal databases.

The Electronic Frontier Foundation, under the Freedom of Information Act, obtained records from the bureau showing that the database will have as many as 52 million images by next year and include pictures of innocent people. The database is expected to flourish in numbers. There were more than 12 million arrests in 2012, according to the latest FBI figures available. That's one arrest every two seconds.

The power of facial recognition technology was underscored in August, when the FBI announced that a US fugitive on the lam for 14 years in connection with child sex charges was apprehended in Nepal after authorities scanned his FBI "wanted" poster with facial recognition tech. The arrest of Neil Stammer was a result of the State Department testing facial recognition software to detect passport fraud. The department scanned into the biometrics database of Stammer's most-wanted poster. Stammer's face matched a person with a different name on his passport, and the fugitive was easily traced to Nepal.

The Electronic Privacy Information Center, citing FBI documents obtained via the Freedom of Information Act, said the technology could fail 20 percent of the time, which the group said could lead to innocent persons becoming the subject of police investigations.

The Next Generation Identification system kicked off in 2011, when it focused on enhancing fingerprint technology, the FBI said.

"The NGI system has introduced enhanced automated fingerprint and latent search capabilities, mobile fingerprint identification, and electronic image storage, all while adding enhanced processing speed and automation for electronic exchange of fingerprints to more than 18,000 law enforcement agencies and other authorized criminal justice partners 24 hours a day, 365 days a year," the bureau said.

The Electronic Frontier Foundation, meanwhile, said the FOIA documents it obtained from the bureau show that it's not just mug shots that will be included in the database.

One of our biggest concerns about NGI has been the fact that it will include non-criminal as well as criminal face images. We now know that the FBI projects that by 2015, the database will include 4.3 million images taken for non-criminal purposes.

Currently, if you apply for any type of job that requires fingerprinting or a background check, your prints are sent to and stored by the FBI in its civil print database. However, the FBI has never before collected a photograph along with those prints. This is changing with NGI. Now an employer could require you to provide a “mug shot” photo along with your fingerprints. If that’s the case, then the FBI will store both your face print and your fingerprints along with your biographic data. In the past, the FBI has never linked the criminal and non-criminal fingerprint databases. This has meant that any search of the criminal print database (such as to identify a suspect or a latent print at a crime scene) would not touch the non-criminal database. This will also change with NGI. Now every record—whether criminal or non—will have a “Universal Control Number” (UCN), and every search will be run against all records in the database. This means that even if you have never been arrested for a crime, if your employer requires you to submit a photo as part of your background check, your face image could be searched—and you could be implicated as a criminal suspect—just by virtue of having that image in the non-criminal file.

The bureau and the Department of State contracted with a company called MorphoTrust to build the program.