WATERVILLE – An Athens teen-ager, described as a criminal mastermind by some and a naive dreamer by others, will not be tried as an adult for a bank robbery he admitted committing last year.

Nathanael Blevins was 17 when he committed the crimes and the law still considers him a juvenile, District Court Judge Vendean V. Vafiades said Wednesday.

Blevins, now 18, has served nearly six months at the Northern Maine Juvenile Detention Facility in Charleston. He will serve another eight to 12 months at the Maine Youth Center in Windham, Vafiades said in her 25-page decision. He must receive counseling and 11/2 years of after-care following his release.

“The court determines that Nathanael is aware of the seriousness of his behavior, has a growing sense of its impact on his victims, family and the community, and is likely to emerge from his incarceration as a productive member of society,” the judge said.

Blevins’ attorney, Thomas A. Tilton of Waterville, declined to comment on the ruling. “It’s still a juvenile case, and I still have no comment because of that,” he said.

Assistant District Attorney James Mitchell disagreed with the decision, saying Blevins belongs in the adult system because his crimes revealed planning and maturity beyond his years.

Before his heists, he read books about criminals: “The Great Train Robbery,” about an aristocratic Englishman’s attempt to steal gold bullion; “Stopwatch Gang,” about Canadian bank robbers; and “Where the Money Was,” by Willie Sutton, the best-known bank robber of his era. He also searched the Internet for more information.

A court psychologist found that Blevins was preoccupied with robberies and living in a fantasy world, but he was not thinking about the consequences of his actions. Blevins suffers from low self-esteem, depression and alienation from family, said David Booth, a psychologist. He is not violent or aggressive, he said.

Blevins will continue his education at the Maine Youth Center, Vafiades said, as well as his emotional and psychological development and rehabilitation.

“He has no criminal history and will return to the community with a high school education, an awaiting supportive family, a life plan and vocational goals,” the judge said.

Blevins’ father, a pastor in Athens, said he and his wife, Melissa, were happy with the decision. “There are no words to tell you how glad we are, but of course, we’re parents,” Roy Blevins said. “That doesn’t mean we’re not sensitive to the hurt that’s been caused to the community in this.”

At a hearing last month, the younger Blevins admitted he robbed Gardiner Savings Institution in Waterville on Oct. 6. He handed a teller a note demanding that money be put in his Bible bag. He walked away with nearly $6,000, took a bus to Boston, then to Canada, and was apprehended Oct. 13 by Canadian police in a suburb of Toronto.