Using those identifiers, law enforcement can run software to search a suspect's computer for known child porn, but not new child porn, forensics experts said.
Victor Fay-Wolfe, director of the Rhode Island Digital Forensics Center, said his center will release a downloadable program next week that is similar to Adroit that could help law enforcement scan a hard drive for porn.
With funding from the National Institute of Justice, the program examines images for skin tone, edges that indicate human forms and other features.
"All of those weighted together allow the software to determine together if it's porn," he said.
But he added that automating child pornography detection has proved especially challenging, in part because child porn laws not only apply to offenders, but those developing technology intended to help prosecute them.
"Child pornography is a different story," he said. "We're finding it to be an extremely difficult problem."
Detection software needs a straight on image of a face, which you don't often get in child pornography, he said. Photos of genitalia would be more effective, but using those is illegal.
"That's the best we can write without having contraband," he said.
Fay-Wolfe said programs created to detect child pornography are at most 60 percent accurate. But even that could potentially help law enforcement, he said.
"Even 50 percent accuracy is a big savings of time to them," he said. "Some detection is better than none, when they have nothing to help them."
Still, though technology may help an investigation into a child porn suspect, law enforcement officers say that it's ultimately the human investigators who makes the biggest difference.
"The skill and experience of our investigators, along with the intelligence we develop, is our strongest asset in pursuing these criminals," said Peter Grossgold, an FBI special agent who supervises the squad that investigates child pornography cases in the New York office.