CEDAR RAPIDS, Iowa -- A judge sent an influential youth basketball coach to prison effectively for the rest of his life Thursday, saying he secretly collected sexual images of 440 boys and molested more than a dozen over a 20-year period.

U.S. District Judge C.J. Williams sentenced former Iowa Barnstormers coach Greg Stephen to 180 years in federal prison, the maximum penalty he faced on sexual exploitation and pornography charges. Williams called Stephen's crimes horrendous, saying he abused his position of trust to prey upon boys who saw him as their ticket to college basketball.

"The harm the defendant caused to the children is incalculable and profound,'' Williams said from the bench in federal court in Cedar Rapids. He said Stephen's conduct was "of such an extreme nature'' that it warranted an effective life term.

The sentence, handed down after a daylong hearing, capped one of Iowa's largest and most stunning sexual abuse prosecutions involving youth sports.

Stephen, 43, had worked with Iowa's most promising youth players as a co-director and coach of the Barnstormers, which was sponsored by Adidas and competed nationally. Almost all of the high school seniors he worked with earned college athletic scholarships, including to play at universities such as Iowa, Northern Iowa and Wisconsin.

Stephen secretly amassed a digital collection of thousands of sexual videos and photos of his players and their friends. The majority of the victims were coerced by online personas in which Stephen pretended to be a teenage girl and enticed them to provide videos and photos of themselves masturbating; these were relationships that went on for years. Others were surreptitiously recorded by devices that Stephen placed in bathrooms in hotels and his home or disrobed by Stephen and photographed while they slept.

On at least 15 occasions between 1999 and 2018, Stephen touched boys, often as he shared a hotel bed with them during trips to tournaments and professional basketball games, according to Thursday's testimony.

One of the boys later told police he kept quiet for years because he believed Stephen was his link to college basketball coaches for whom he dreamed of one day playing, Division of Criminal Investigation agent Ryan Kedley testified.

"He decided to swallow that experience and not tell anyone,'' Kedley said.

Federal prosecutors and the mothers of two victims had urged Williams to impose a life sentence on Stephen, who helped manage his family's auto dealership in Monticello, Iowa.

"He believed you held the keys to the basketball kingdom,'' said the mother of one boy, who was tricked by Stephen into providing images of himself masturbating. "My son trusted you and you destroyed that. ... How dare you use basketball for your selfish, despicable, disgusting, self-seeking motivation.''

Stephen's defense had asked Williams for leniency, seeking a sentence of no more than 20 years in prison followed by intensive supervision on release. His lawyers and experts argued that his conduct was primarily as a voyeur, not a hands-on molester, and that he was at a low risk to reoffend now that he has been caught. Stephen's father, Roger, said his son had helped him run the dealership after his brother was killed in a traffic accident seven years ago.

"He is not a threat to society,'' he said.

Stephen apologized to his former players and their parents, saying, "I am disgusted. The things I have done are repulsive and wrong.'' He said his greatest regret was that his accomplishments as a coach were now tarnished.

Williams rebuked Stephen for that comment, saying his biggest regret should be the harm he caused the boys and their parents.

Stephen came under investigation after his former brother-in-law found one of the recording devices while performing remodeling work at Stephen's home in Monticello last year and gave it to police. Eventually, investigators found a hard drive that contained more than 400 file folders, each with the name of a different boy, that contained thousands of images collected over more than a decade. A trove of additional pornographic material was stored in a file that was waiting to be organized, Kedley said.

Stephen, who has been jailed since his arrest last year, pleaded guilty to multiple counts of child sexual exploitation and production of child pornography charges. He is expected to appeal his conviction and sentence, in part by arguing that the seizure of the recording device by his former brother-in-law violated his privacy rights.

California attorney Mark Haushalter said he has been retained for that appeal.

"We believe there is merit based on the unusual and extremely unorthodox behavior of law enforcement in this case,'' he said.