A Plymouth man will spend nine years in federal prison and then a decade of supervised release and have to register as a sex offender for cyberstalking more than a dozen women, turning their lives into what the prosecutor called “waking nightmares.”

A hush fell over Courtroom 21 in the federal court in Boston on Wednesday when U.S. Marshals brought James Florence Jr., 37, in for his sentencing hearing a little before 2 p.m.

The slight man with buzzed hair and a goatee barely glanced up at the gallery full of people — his victims, their families and friends who came to support them — before sitting between his two public defenders and dropping his head.

Florence pleaded guilty in April to seven counts of cyberstalking and one count of child pornography, as at least one of his victims was a minor girl whom he terrorized as mercilessly as the grown women, according to court documents and the victim impact statements shared in court.

“I’m so glad this is over, but I’m sure the effects will be everlasting,” one of his victims shared in court before sentencing.

This victim, the sixth to provide a victim impact statement in court — four more were read aloud by prosecutor Luke Goldworm — described how, at the time of Florence’s active harassment of her, she had her home so locked down that her boyfriend described it as “Fort Knox Jr.”

She had met Florence at 9 or 10 years old, she said, and when fake, artificial intelligence, or Photoshop-generated pornographic images of her began cropping up across the internet, she never suspected her long-term, close friend.

“Gross” men would come up to her in her workplace, or send her “disgusting” messages online. The woman who had earned two degrees “to prove her worth” was turned down for jobs time and again because she had to disclose that if you did a Google search of her name you would find nude photos, “but that it wasn’t really me.”

The trusted friend, allowed into her home, used the opportunity to steal her underwear and sell it online to like-minded users. Most of the quotes and images recording his abuse are too explicit to be shared in the newspaper.

It was all a similar pattern of behavior described by the other women in their own statements to the court, but with their own descriptions of his harms and their continuing effects because, as one of them said, “the internet is a permanent space.”

“He led this duplicative double life, this secret betrayal, all while hiding under the very blanket of confidence and deference he was afforded by the very women he victimized in the dark,” prosecutor Goldworm summarized in his sentencing memo and reiterated in court in an impassioned argument for harsh punishment. “However, in the light of day it is crystal clear that Florence used his computer skills and ingenuity to turn the lives of these women, and the people around them, into waking nightmares.”

The statements had an effect: U.S. District Court Judge Richard G. Stearns accepted the prosecution’s recommended sentence of 108 months, which is nine years, in prison. He said that the sentence was “an adequate one and could be longer.”

Stearns said that the term should be followed by a longer term of supervised release, because he had “less confidence” that Florence, a skilled tech professional, would discontinue terrorizing women if given the opportunity to do so. He imposed a 10-year term of supervised release.

Stearns also expressed doubt that anyone could provide “any psychological insight into Mr. Florence’s Jekyll and Hyde mentality,” in which the man who was close and trusted by each of his victims operated in the dark.

“I want to sincerely apologize to everyone here. Everyone who came today, the victims, families, and all of their friends,” Florence, who not once looked up from the table during the hearing, said for himself before sentencing. “I have listened to your words here today and I will use them to be better and become the person you need me to be. I am truly sorry.”

It was a message anticipated by another of his victims, who remembered “Jimmy” as a constant presence in her life, as “a second brother, who I loved and thought loved me back.”

“Even now, I talk about him as two different people,” she said. “Jimmy will always be my Jimmy, but James I can never forgive.”

“He chose to torture women for a hobby, and that’s disgusting,” she concluded. “The effects of his crime do not end just because he’s in a cell serving time.”

Harassing messages discovered during the police investigation into James Florence Jr., of Plymouth, who will spend nearly a decade in federal prison for vicious cyberstalking campaigns. (Courtesy/U.S. District Court)