At his federal sentencing hearing, former Saybrook Master and convicted child pornographer Antonio C. Lasaga wanted leniency. Instead, he received a 15-year federal prison term.

But the former Yale geochemist is not done fighting for a reduced sentence.

Lasaga’s attorney, Diane Polan, filed a motion in late February to appeal his federal sentence on convictions of possession and receipt of child pornography — including video and still images featuring Lasaga and the boy he molested.

Polan said U.S. District Judge Alvin W. Thompson abused his discretion when he factored the “extreme psychological injury” Lasaga caused the victim into the length of the sentence. This was inappropriate, Polan said, because the harm done to the victim was addressed in state court, where Lasaga pleaded no contest to multiple counts of sexual abuse.

The pain is legally distinct from the pornography, Polan said, and she is ready to argue this before an appeals court.

Lasaga’s appeal revolves around a judicial procedure known as an “upward departure.” According to federal law, sentencing is determined by two factors: the defendant’s criminal history and the severity of the offense for which he is being imprisoned. Given these two factors, a judge need only glance at a ready-made table to find the exact sentencing range.

But if the judge feels that the sentencing guidelines do not adequately reflect the nature of the crime and the criminal, he can add to or subtract from the length of the recommended sentence. That is, he can “depart” upwards or downwards from the prescribed sentence.

In Lasaga’s case, Thompson used the “extreme psychological injury,” coupled with the sheer volume of pornographic images found on his computers, to depart upwards from a recommended maximum term of 11 years to the awarded sentence of 15 years.

While Polan said the departure was unwarranted, University of Connecticut Law School professor Steven Wilf said Thompson does not have any explaining to do.

Wilf, an expert in criminal law, said a federal judge has more discretion in the sentencing phase of a trial than he does in conviction. In fact, he said it is the judge’s responsibility in determining a sentence to assess all of the defendant’s attributes that might make him a danger if he were not imprisoned.

“The ruling here does not seem terribly troubling,” Wilf said. “The judge has to take all of his proclivities into account when rendering his sentence.”

But Polan said she sees it in precisely the opposite way.

She said the federal sentencing guidelines, which took effect in 1987 and have since undergone several revisions, remove virtually all of a judge’s independent decision-making power. While the spirit of the guidelines is to make sure defendants with similar backgrounds who commit similar crimes receive similar sentences, Polan said, they have in practice sometimes done more harm than good.

“The guidelines are very difficult to understand and interpret,” she said. “A lot of the time they don’t actually eliminate the disparity they are supposed to.”

Some of the facts support Polan’s assertion. From 1998 to 2000, 11 people have been convicted of federal crimes involving pornography in Connecticut, and the average sentence received has been slightly more than two years, according to figures provided by the U.S. Sentencing Commission.

According to the 2001 Federal Sentencing Guideline Manual, in order to upwardly depart from sentencing guidelines, a judge needs to find that the victim “suffered psychological injury much more serious than that normally resulting from commission of the offense” for which the defendant is charged.

Since the kind of abuse involved in Lasaga’s case normally causes grave emotional damage, Polan said, it is hard to determine what is “much more serious” relative to the already high level of abuse.

“It has to be more extreme than you would expect,” Polan said. “For these crimes [of sexual abuse], you would come in expecting a great deal of psychological injury.”

Polan also said she also plans on appealing Lasaga’s 20-year state sentence but has not yet formulated a specific plan of attack.

“I’m very disturbed at what went on in both hearings,” Polan said. “I think we have grounds to contest it.”