Mary Bowerman

USA TODAY Network

Kansas serial killer Dennis Rader seemed like the average family man to his friends and those who attended church alongside him, but beneath his seemingly ordinary facade was a man who called himself the BTK (Bind, Torture, Kill) Killer.

A book released on Sept. 6, by forensic psychology professor Katherine Ramsland provides insight into Rader’s mind and what drove him to kill ten people in the Wichita-area between 1974 to 1991.

Over a five-year period, Ramsland spent hours speaking with Radar, who was arrested in 2005, on the phone to piece together his story.

Here are five creepy things we learned from Ramsland's book Confessions of a Serial Killer: The Untold Story of Dennis Rader, the BTK Killer.

1. Rader had plans to kill an 11th victim.

In 2005, Rader told police that he had been stalking and planning on murdering an 11th victim. At the time, this information was not revealed to the public.

Rader went into horrific detail about the way he planned to torture and kill the victim.

2. Rader "evolved" into a serial killer.

Before Rader began planning and carrying out murders, he told Ramsland he started out small.

He unsuccessfully tried to kidnap someone, and often broke into people's houses because even though they weren’t there, it made him feel powerful, according to the book.

He said a lot of his lust to kill and kidnap stemmed from “early feelings of helplessness,” when he lost his job and was living off his wife's income. He felt emasculated, “but breaking into a house made him feel powerful,” Ramsland said in a phone interview.

“He would stalk around, look into windows,” Ramsland said. “It was a gradual evolution of things that made him feel aroused and powerful, feelings that he preferred over ordinary life.”

50 years later, man arrested in wife's death

3. Rader thought he was going to get caught.

After killing four members of the Otero family, Rader was shocked the police did not catch him.

Ramsland said Radar never thought he was going to get away with his first kill. He killed the Otero family during daylight hours in their neighborhood and said he made many mistakes.

“He even left something behind and went back for it, and he expected to get caught,” she said.

Rader told Ramsland that when he realized he was going to get away with the murders, he felt even “more powerful, like he was invisible.”

“He thought of himself as a spy, like someone who walks amongst people and people don’t know his mission, they just think he is an ordinary person,” she said.

Serial killers in the U.S.: a legacy of murder

4. Rader was constantly searching for the perfect victim.

Rader's first kill didn't go the way he planned, so he wanted to try again, according to Ramsland.

“He had wanted to take pictures of the first murder, but he didn’t have a camera, and a number of things were missing,” she said.

He found a second victim, but her brother came home with her and Rader and the brother struggled with a gun.

Ramsland said Rader escaped and continued his search for the perfect victim. But even after he found one, he was “addicted,” and always ready for the next.

5. He had a “project” list of people he wanted to kill.

Ramsland said Rader sent her his list of what he called “projects,” or people he had targeted and wanted to kill.

“There were like 55 people on the list,” she said. “A lot more than he actually killed.”

She said Rader used a metaphor for his project list and compared himself to “a fisherman who goes out, and sometimes you catch and sometimes you don’t.”

So while many believe that Rader was not killing or stalking during the years before he emerged into the spotlight again in early 2000, he actually was out looking for new “projects,” but failed in getting them, according to the book.

“He had details, dates, names places of these people,” she said. “You don’t just get rid of an addiction.”

Follow @MaryBowerman on Twitter.