The federal prosecutor called him the “embodiment of evil.”

The judge in the case described him as a “predator of children.”

Kevin L. Donaldson, in contrast, denied his guilt right up to the moment he was sentenced Friday to 40 years in federal prison for sexually assaulting three minors, all of them members of his family.

“There are few crimes that are so revolting, so disturbing as this one,” Assistant U.S. Attorney Aaron J. Mango told the judge. “He shattered any chance these three victims would have a normal childhood.”

U.S. District Judge Richard J. Arcara, who presided over Donaldson’s two-week trial, described the case as both unique and disturbing.

“I’ve been in this business some 47 years and this case presented facts that quite frankly were difficult to hear,” Arcara said.

It was a case of three victims who, one by one, took the stand and testified about Donaldson repeatedly raping or assaulting them when they were underage and often while they traveled with him on trucking trips across the country from 2004 to 2007.

One of the women testified that during one out-of-town trip, Donaldson raped her each day they were gone.

Donaldson, 48, a former Salamanca resident who already is serving four years in state prison for rape, insisted Friday that the stories of rapes and assaults were made up.

“I wouldn’t steal away their innocence,” Donaldson told Arcara. “I’m not the piece of crap I’m made out to be. I’m asking you to please show mercy on me. I did not do this, Judge Arcara.”

Arcara didn’t buy it.

He sentenced Donaldson to 40 years, short of the life term he could have given him, but a sentence that could keep him in prison well into his 80s.

Throughout the trial, Mango and Assistant U.S. Attorney Michael DiGiacomo portrayed Donaldson as a sexual predator whose sole motivation in bringing the girls on trips was for the purpose of having sex.

They also painted him as abusive and manipulative and to make their point played a recording of a phone conversation that suggests Donaldson tried to get one of the victims to blame someone else.

“He used fear, intimidation, emotional control,” Mango told the judge Friday.

Donaldson’s defense attorney countered by suggesting the women’s stories have changed over the years and that their testimony was unsupported by physical evidence or other testimony in the case.

“He’s maintained his innocence throughout this entire matter,” said Robert N. Convissar, Donaldson’s defense lawyer, in pleading for leniency.

Donaldson was found guilty in August of five felony charges of transporting a minor across state lines for the purposes of sexual activity and one felony charge of witness tampering.

He indicated Friday that he will appeal his conviction.