For Kerri Rawson, a knock on her apartment door in February 2005 would prove to be life-changing for all the wrong reasons.

It was then that Rawson found out the FBI had arrested her father Dennis Rader and accused him of being the man known as the BTK Killer -- BTK standing for “bind, torture and kill.” He would later admit to murdering 10 people -- mostly by strangulation -- in Wichita, Kan., between 1974 and 1991.

Rader became known as the BTK Killer after sending letters to the police and local media where he detailed the killings and mocked police investigations. He was arrested on Feb, 25, 2005 after police tracked him down using data that was left behind on a floppy disk he sent to a local TV station.

It was shortly after Rader’s arrest that Rawson found out the man she knew as her father, a member of the Christ Lutheran Church and a local Cub Scout leader, had been living a secret life as a serial killer.

“Initially, I was in five days of shock,” Rawson told CTV News Channel on Monday. “You’re just trying to comprehend: ‘Why would the FBI be here?’ You’re racking your brain.”

Rawson’s recently released book, ‘A Serial Killer’s Daughter: My Story of Faith, Love and Overcoming,’ details how a seemingly normal life came crashing down and how she’s been able to cope with the ordeal.

Rawson said she’s dealt with post-traumatic stress since her father’s arrest and spent years in and out of therapy. She discovered putting her thoughts into writing proved therapeutic, which became the idea behind her book.

“I was internalizing everything I was going through and almost having to hide who I was,” she said. “I finally just had enough and started speaking up in my hometown Wichita, Kansas paper, and after I started speaking up, I realized there was power and healing in sharing my own story.”

Rawson says she still writes to her father a few times a year, but hasn’t had the courage to visit him in prison.

“I would like to see him before he gets any older -- he’s 73,” she said. “He’s my father and I still love my father. I would like to see him and hug him one more time.”

Rawson says she’s been the victim of some internet trolls since her book has come out, but adds the reception has been largely positive.

“I’ve got an inbox on social media just full of people encouraging me and cheering me on,” she said.