Raising the Columbine Shooter

From the years 1973-1999 Columbine High School was like any other High school, like most schools they practiced lockdowns. But no amount of practicing lockdowns would prepare them for this. On April 20th, 1999 my son and his friend Eric entered Columbine High School and killed 15 kids a teacher, and  themselves.
When I woke up April 20th it was a normal morning. Get dressed, pour my coffee and eat breakfast, but Dylan walked out the door with a quick and barely audible “Bye”. Most teenagers have bad days and I blamed it on that but little did I know it was a lot more than just a bad day.
Later that day when I was at work I got a call from an unknown number.
“Hello?” I answer not knowing what to hear next. Most unknown calls were calls from telemarketers or family members I’ve forget about. But no call was anything like this call. 
“Hello Mrs. Klebold this is the Jefferson County Police Department, we regret to inform you that your son has killed himself”. My stomach dropped, the whole room spun around me as if I was on a carousel. I couldn't believe what I just heard, it was like a vacuum just sucked everything I had out of me, I didn't have the energy to respond though I was on my second cup of coffee. “We also regret to inform you that your son has also killed 12 students at Columbine High School”. I couldn't believe what I was hearing, my body went numb like when you sit on your leg too long and you can't feel it, nothing felt real.
The next thing I know is I’m laying on the couch limp watching the news seeing my son murder 12 of his own classmates and a teacher. How could I have not known? How could my son be capable of this? How could I let this happen? I had so many questions and zero answers. I heard a loud knock on the door, but my body was too limp to answer. Another loud knock, I drag my body off the couch and trudged my body to unlock the door only to see 3 policemen waiting at the door. They help my lifeless body to the couch where they begin to ask me questions about Dylan.
“Did you have any idea he was planning to do this?” “Did you know about Dylan and Eric purchasing the semi-automatic rifles?” “Did you know Dylan and Eric wanted to kill themselves?” The questions kept on piling and piling like bricks being laid on me, each making my chest heavier and heavier. I only had one answer to all the questions they kept on asking me.
“Of course I don’t know, what kind of a mother would I be to let my kid murder 12 students and kill himself?”. I felt my eyes sting and start to fill up with tears like when you put in eye drops. I had no control and I felt tears stream down my face. My brain goes back to the nights Eric would sleepover and they would stay up watching violent movies. Could this have been a sign? When the police searched his room they found a journal. The journal had thoughts I never thought Dylan had. Dylan said that he wanted to kill himself. The boy that I had raised, I felt like I did everything wrong as a mother.