Rader's name apparently surfaced again in recent months as detectives studied surveillance videos from businesses located near the spots where BTK dropped some of his mocking communications.
"They kept seeing this Park City animal control officer's van," said Robert Beattie, a local author who is writing a book about the case and who has extensive contacts with investigators.
Rader, who is married with two grown children, works as the animal control officer in Park City, a working-class suburb of ranch homes and fast-food restaurants about 10 minutes north of downtown Wichita. Part of his job was citing residents for violating municipal codes.
Although some of his neighbors said he was friendly -- and he was well-respected enough to serve as president of his church council -- others called him mean and arrogant. "He wore a badge and would swagger around the street like he was above the law. I always considered him a bully," said James Reno, 42, who has lived across the street from Rader for more than a decade.
Maricela Cano, 23, who lived around the block from him for more than two years, said: "I can't tell you how many times he made me cry. If he was outside, I would stay indoors and hide." She said Rader constantly harassed her about her dogs, until she and her family moved across town.
On Saturday morning, her 5-year-old son was watching TV coverage of BTK when a picture of Rader flashed on the screen.
"He turned around and said, 'Mommy, look. It's the man who took away our dog,' " Cano said. "It freaked me out."
Rader was so rigid about code enforcement, neighbors said, that he carried around a ruler to measure the height of grass on lawns he thought looked unruly.
Investigators noted that BTK was meticulous: When he broke a window to get into a victim's house, he swept up the glass. In a few of his letters, he made a point of commenting on how tidy -- or dirty -- he found the victims' homes and cars.
Rader was arrested as he was driving through Park City just before noon Friday. Later in the day, police seized computer equipment and numerous plastic containers from his single-story home. A mobile police laboratory was still parked in front of the house late Saturday.
Authorities would not say whether Rader has talked to them.
BTK, however, has been talking loudly, if cryptically, for decades.
