BANGOR – Law enforcement agencies in Maine may soon be able to identify a lost child or adult with a simple scanning of an eye.

Under a new program in place in 21 states and getting its start in Maine in Penobscot County, a digital camera would take a picture of the unidentified person and compare it to a local or national database.

“A match means we will be able to immediately identify the person that we have in our custody or our care,” Penobscot County Sheriff Glenn Ross told reporters Thursday during a press conference where the Children’s Identification and Location Database project was unveiled.

Paid for through a $25,000 grant from the Stephen and Tabitha King Foundation, the system is intended to help law enforcement agencies identify a missing child who winds up in their custody or an Alzheimer’s disease patient who has wandered away from home.

Nationally, more than 2,000 children are reported missing each day, while in Maine, about 150 children are reported missing each month, according to state statistics. Many of them return home a short time later, state police spokesman Stephen McCausland said earlier this week.

Instead of fingerprints, the computer compares the iris of the eye, which is even more unique to an individual than a fingerprint, Kevin O’Reilly, vice president for Biometric Intelligence & Identification Technologies, the Massachusetts-based company that has developed the system.

The computer-based system not only can distinguish between twins but also between a person’s left and right eye. That is because from birth to about 18 months, a person’s iris undergoes a lot of growth and the slow process of rips and tears leaves behind a signature pattern.

“The iris, like the fingerprint, has unique characteristics,” Ross said. “No two are alike.”

Despite both fingerprints and irises offering a way to identify a person, it could take hours, sometimes days, to complete a fingerprint search, Ross said. The iris biometric recognition technology is much quicker, taking only a few seconds to check a local database. Connecting to the national database, which currently has about 70,000 entries and is expected to grow to about 3 million in two years, takes a little bit longer.

The system can be used on scene and the information later downloaded to the national database hosted by the nonprofit organization, The Nation’s Missing Children Organization and National Center for Missing Adults.

The system can fit in a case a somewhat larger than a briefcase, and Ross said portability means it can be used elsewhere and can dovetail with other programs in place by other law enforcement agencies and social service agencies.

Bangor police Lt. Steve Hunt said the CHILD project offers a tremendous application for identifying missing autistic children who can’t communicate verbally and who are not wearing an identification bracelet.

“We would be able to use this to get them safely home,” said Hunt, whose department is developing a database for autistic children.

And it’s not just children who would benefit.

More than half of Alzheimer’s patients wander away from their homes and eight out of 10 do it more than once, according to Peg Gagnon, information and outreach specialist with the Maine Chapter of the Alzheimer’s Association.

Ross said registration programs for adults and children are in the works.

The sheriff acknowledged that the system might have limited use for now outside of identifying missing children and adults.

With a law enforcement database of 600,000 people already in place, Ross said he doesn’t expect the iris system will be used in criminal law enforcement right away. It could be used to help identify inmates or visitors to the Penobscot County Jail, as it has in other states.

The cost of $25,000 also may put it out of the reach of some agencies, although O’Reilly said his company works with agencies to find funding.

Still, Ross said the system easily could prove its worth by helping families find lost loved ones.

“It’s something that comes with a big payoff if it’s used,” Ross said after the press conference. “If we just identify one missing person, then the program would pay for itself.”