The affidavit describing Brown's extensive Internet chats about eating children is grotesque, even by the jaded standards of child abuse investigators. Brown and Arnett were discovered during an international child pornography crackdown that has led to 40 arrests in six countries. The pair's exchanges stood out to investigators.

"In my time here at this agency," Feinstein said, "I've never seen anything this gruesome."

Using online monikers that investigators traced to their computers, Brown and Arnett discussed killing — what they called "snuffing" — children as young as 2. Arnett described what different human body parts tasted like, roasted or cooked in a skillet, according to the complaint.

In one chat cited in the complaint, Arnett described drowning a little girl, and in another, he and Brown excitedly talked about a photo, shared by Arnett, of a 3-year-old girl being strangled.

"That's how I would enjoy doing" the unidentified boy from Gulf Coast Church, Brown said.

Morris, the church pastor, said the parents of the boy are "shocked and perplexed" by what federal authorities say Brown wanted to do to their son. "They're just reeling. It's very difficult for them to hear," Morris said.

He would not identify the boy or disclose his age, and said he is not sure if the boy himself has yet been made aware of the charges against Brown.

Federal authorities have presented no evidence that Brown actually harmed children. But the criminal complaint against him refers to two previous run-ins with local police that did not lead to charges.

In 1998, a Pinellas County sheriff's deputy stopped Brown for a traffic violation and observed boy's underwear between his front seats. Brown said he used the underwear to dress his puppets.

In 2010, Largo police were called to Brown's house by a neighbor who had suspicions about his habit of driving boys around. No arrest resulted.

Brown worked for years for the Christian Television Network in Largo, the state's oldest Christian broadcasting station. He performed with puppets on a Captain Kangaroo-style show called Joy Junction. In one episode, a video excerpt of which is available online, he operates a puppet that talks disdainfully about how some bad kids tried to show him pornography.

A receptionist at CTN's headquarters in Largo said Tuesday that the station had no comment on Brown's arrest, and would not make other officials available or allow a reporter into the building. It is not clear whether Brown still works there, though his Facebook page states he is employed as a control operator at the network.

Largo recreation program manager Warren Ankerberg knew Brown in his capacity as the leader of Smuppets, a city-sponsored senior citizen puppet troupe. (The name is a combination of "seniors" and "muppets.") Ankerberg said Brown was a skilled teacher and had a large collection of elaborate marionettes.

"He was always a gentleman," Ankerberg said. "He always seemed to be very gentle, very considerate of others."

Brown's neighbors at Whispering Pines mobile home park described him as reluctant to interact with adults, but quick to socialize with the park's many children.

Park resident Michael Gonzales said his live-in girlfriend's 13-year-old son sometimes attended Brown's pizza-and-church evenings. Brown had come to their house beforehand to seek their permission for the boy's participation, with a demeanor Gonzales described as "overly, excessively nice."

Brown lived with his parents in the mobile home until they died at least 10 years ago and now lives alone with a cat, said next-door neighbor Laurajane Schade. Sometimes he could be seen passing a solitary afternoon at the park's pool or riding his bicycle down its narrow streets.

Stacy Gaughan, who lives across the street from Brown, said she would often see him driving teenage boys to Gulf Coast Church in a van that the church lent to him. On Halloween, she said, he would crank up a cotton candy machine in front of his house and spend all night serving trick-or-treaters.

"We all thought he was weird," Gaughan said. "But we had no idea the things he was thinking."