TAMPA — A federal judge sentenced a Largo church puppeteer who wrote online about sexually torturing and eating children to 20 years in prison Monday, punctuating a criminal case whose unsettling details raised difficult questions about free speech and due process.

Ronald William Brown, a 58-year-old professional puppeteer who lived at the Whispering Pines mobile-home park, was also sentenced to a lifetime of supervision following his release. He will be required to register as a sex offender and be restricted from access to areas frequented by children, U.S. District Judge James D. Whittemore ruled.

Brown had only pleaded guilty to possessing and receiving child pornography and was never charged with doing direct physical harm to anyone. But Whittemore agreed with prosecutors that the unusual circumstances of his case warranted an upward departure from the prison term of 6.5 to 8 years suggested under federal sentencing guidelines.

In addition to receiving pornography, federal agents found that Brown had engaged in protracted online discussions with other child-cannibalism enthusiasts about kidnapping, killing, cooking and eating children, including a specific boy at his church in Largo.

Prosecutors introduced into evidence a photograph of the boy that Brown had labeled in the style of a butcher's diagram, with different parts of his body labeled as "steaks" and "shanks."

"Perverted is not a strong enough word, Mr. Brown, to describe what you've been engaged in," Whittemore said Monday. "Depraved isn't strong enough. … All the adjectives seem inadequate."

Brown's attorneys had argued for leniency in sentencing, noting that Brown had no criminal record and had spent decades of his adult life working around children without acting on the gruesome impulses he professed.

"He lives in a fantasy world," Eric Kuske Leanza, Brown's Tampa-based attorney, told the judge Monday. Leanza said he was being placed in the difficult position of defending thoughts his client had never translated to actions. "I can't defend things that never occurred," he said.

Brown's puppet shows were well known in Pinellas County, where he worked with various community groups. He once had a regular job performing with a ventriloquist's dummy named Marty on a Christian Television Network children's show called Joy Junction.

Prosecutors argued that Brown's was not a garden-variety pornography case. Authorities say he had multiple images of dead children and children in bondage in his computer files. He pleaded guilty to eight counts of possessing or receiving child pornography in March.

"Mr. Brown's interest is not just in children," Assistant U.S. Attorney Amanda Kaiser said. "It's in dead children, which is fairly unusual, I think." Kaiser said Brown had even gotten in touch with a local funeral home seeking work so that he could be around corpses. Brown had also bragged in one chat about molesting a boy in a pool, Kaiser said.

Documents filed last week by prosecutors also assert handwritten journals found in Brown's home show he had "a long pattern and history of obsessing about individual boys" as far back as 1979, some of whom he knew through his "puppet ministry" at Pinellas County churches.

In 1993, the journals show, Brown became "obsessed" with a boy he knew through his puppet work and "repeatedly drove past the Dunedin Middle School at 4 p.m. hoping to see" him. He indicated in the journals that he "liked" another boy but "got mad at him for losing interest in the puppets."

Kaiser said the patterns of infatuation, obsession and resentment in the journals were similar to those in a "teen's diary," but for the frequent references to puppets and Brown's musings about killing one of the boys who had drawn his attention.

"Protection of the public is the final and perhaps the most significant aspect of this proceeding," Whittemore said in explaining his ruling. In Brown's case, he added, "the risk is there that that obsession becomes something more than fantasy."

Peter Jamison can be reached at pjamison@tampabay.com or (813) 226-3337. Follow him on Twitter @petejamison.