HARTFORD — Former Saybrook Master Antonio C. Lasaga was resentenced in federal court Friday to 15 years in prison for the possession and receipt of child pornography.

Before the sentence was read, Lasaga, 53, spoke on his own behalf, expressing frustration with his prosecution and with his former attorney.

“Never have I had the chance to say what I’ve meant to say from the beginning,” Lasaga said. “I am amazed at how the legal system manipulates things.”

The new sentence was identical to the one Lasaga received in February 2002 from U.S. District Court Judge Alvin W. Thompson. The United States 2nd Circuit Court of Appeals overturned that sentence in May and sent the case back to Thompson for resentencing.

Lasaga’s federal sentence will run concurrently with a 20-year state sentence he received last year for sexually assaulting a New Haven boy he was mentoring. Lasaga pleaded guilty to the federal charges and no contest to the state charges.

The 15-year sentence is significantly above the federal guidelines of 108 to 135 months for such cases. In issuing the sentence, Thompson made an “upward departure” ruling that the volume of pornography Lasaga possessed, about 150,000 images, and several previous allegations of sexual abuse justified a higher sentence.

“I conclude that there is a lack of appreciation on the part of the defendant of the harm caused to the victims,” Thompson said. “It is apparent to me that [the sentencing guideline] seriously underestimates the likelihood that the defendant will commit further crimes.”

In the first sentencing, Thompson said he thought a 15-year sentence was sufficient. In this hearing, Thompson said he would now have given Lasaga a longer sentence, if the appeals court had given him the authority.

Thompson considered three other incidents of alleged sexual misconduct by Lasaga going back as far as 1981 and involving children as young as 6 years old. The first allegedly occurred at a swimming pool in State College, Pa. The other two allegedly took place at the Hamden Y.M.C.A. in 1986 and 1991, while Lasaga was working as a geology professor at Yale. Though he was never charged in the incidents, they can be used during sentencing to show a pattern.

“There is no doubt as to the identity of Antonio Lasaga [in the incidents],” Thompson said. “He preyed on young boys at public pools.”

Lasaga’s attorney Diane Polan argued that the sentence provided under federal guidelines was sufficient in light of the existing state sentence. She also contended that the state could not prove that the images on Lasaga’s computer represented actual children. But Thompson agreed with assistant U.S. Attorney Kari Dooley, who said Lasaga had admitted the images were actual child pornography when he pleaded guilty.

“He acknowledged that he had so much child pornography that he didn’t attempt to view it all,” Dooly said. “One hundred fifty thousand is conservative.”

Before the sentencing, Thompson offered Lasaga a chance to speak. He spoke excitedly for about 10 minutes before being stopped by Polan.

Lasaga said there was no way he could tell which images were virtual child pornography and which were real. He also claimed that he had never produced child pornography.

“I had nothing to do with them,” Lasaga said.

After Lasaga spoke, Dooley contested Lasaga’s claim that he only viewed, rather than created, child pornography. Dooley reminded Thompson that Lasaga admitted to taking sexually explicit pictures and video of the boy he was mentoring.

“[There] are, in fact, images of a 12-year-old boy whose trust he betrayed and whose life he has altered,” Dooley said.

By law, Lasaga will serve 85 percent of his federal sentence, about 13 years, and then complete the remainder of his state sentence, Polan said. After completing both sentences, Lasaga will be on supervised release for three years. During this time, he will not be allowed to have unsupervised contact with minors or possess or use a computer with Internet access.

Lasaga remained animated and cheerful throughout the hearing, smiling and chatting with Polan. When asked by the judge whether he understood the consequences of violating the conditions of his sentence, Lasaga smiled broadly.

“Absolutely,” he said.

Dooley said she was pleased with Thompson’s decision. Polan said she would appeal Lasaga’s new sentence. The state sentence is also being appealed.