BANGOR, Maine — A federal judge Tuesday rejected a Franklin County man’s explanation that he downloaded and traded child pornography “like baseball cards” so he could understand why his siblings had been molested as children.

U.S. District Judge John Woodcock sentenced Brian A. Hinkley, 29, of Strong to 12½ years in prison. The judge also sentenced Hinkley to 10 years of supervised release after he completes his prison term. In addition, Woodcock recommended to the U.S. Bureau of Prisons that Hinkley be sent to a facility that treats sex offenders.

“The notion that one has to commit sexual abuse [by viewing child pornography] to understand sexual abuse is abhorrent,” Woodcock said in imposing the sentence. “The reason you downloaded child pornography is that you enjoyed child pornography not because you were doing research even though your family rejects such a notion.”

Woodcock found that the more than 600 images Hinkley downloaded contained images of children ranging in age from toddlers to pre-pubescent girls engaged in sexual activity with adults. He also classified the pictures as being sadistic and masochistic.

“You repeatedly, willfully and intentionally downloaded images of young girls in every form of adult sexual activity,” the judge said. “We know not only that you downloaded them, but you traded these images like baseball cards and placed them on a Web site so they could be accessed by other individuals with similar obsessions.”

Hinkley appeared to be fighting back tears as Woodcock explained why he could not impose a lesser sentence. More than a dozen family members and friends sat behind the defendant and wept as the judge rejected their entreaties to dispense mercy with justice.

The judge rejected motions made by defense attorney Joseph Baldacci of Bangor to impose a lesser sentence and tearful pleas from Hinkley’s family that the defendant would not survive prison because of his gentle nature and short stature.

“This is a very difficult, difficult sentencing,” the judge said, addressing Hinkley’s family directly at the end of a 4½-hour sentencing hearing. “I want you to know that I have heard you today and I understand the pain that you have.”

The investigation that led to federal charges against Hinkley began in July 2005 when FBI agents traced images found on the computer of a student at the Citadel, a military school in North Carolina, to Hinkley’s desktop computer at the home he shared with a relative, according to court documents.

Information about the disposition of the North Carolina case was not available late Tuesday.

In a separate investigation the next year conducted by the Maine State Police, more images were found on Hinkley’s laptop computer. He had been using the wireless account of a family friend to download the images.

Hinkley was arrested and charged in May 2007 with two counts of transportation of child pornography and two counts of possession of child pornography. In a plea agreement with federal prosecutors, the transportation charges were dropped. Hinkley pleaded guilty a year ago in federal court in Bangor to the possession counts. He has been held without bail since entering his guilty plea on March 25, 2008. That time will be counted toward his sentence.

The defendant, wearing his long brown hair tied back in a ponytail, a gray dress shirt and dark slacks, asked Woodcock to look “past the circumstances of the case.”

“I’m not a pedophile, I’m not a criminal, I’m not a sex deviant,” Hinkley said. “The abuse my sister and brother suffered [at the hands of an older female baby sitter] caused the need for me to find closure and I went about it the wrong way. I felt that I had to take this upon myself to bear witness to [their] abuse.”

He also said that what started off as a quest for answers turned into an addiction and a compulsion. Hinkley also said that he had been moved by the victim impact statements written by a mother of one of the victims in some of the images he downloaded and saw parallels in how abuse had affected his own family.

Hinkley, however, has been convicted of three crimes in Franklin County — a 1999 juvenile conviction for unlawful sexual touching, a 2003 adult conviction for possession of sexually explicit material while he was student at the University of Maine at Farmington, and a 2006 conviction for failing to register as a sex offender, Woodcock said.

Under the federal sentencing guidelines, those convictions meant that Hinkley faced a mandatory minimum of 10 years in prison and a maximum of up to 20 years. His recommended guideline range was from 12½ to nearly 16 years.

“We take some satisfaction from the fact that the judge sentenced him to the lowest end of the guideline range,” Baldacci said after the sentencing.

“We are also grateful for the recommendation that Brian be sent to a facility where he can get treatment and be protected. The judge was responsive to those issues.”

While Hinkley was being held at the Two Rivers Jail in Wiscasset, Baldacci said, he was attacked and injured by another inmate and suffered a concussion and an injury to his inner ear. The attorney said that is why his client’s family expressed such concern for his safety in federal prison.