In the letter he states that father Sam rapes kids and drinks their blood. He also states he is in another wavelength programmed to kill. Read the letter it is blatant.

http://www.lettersofnote.com/2009/10/yours-in-murder.html?m=1

I believe this is exactly what they do to the Isis Terrorist Suiciders. Programme them to kill and be kill. Berkowitz Son of Sam was into satanism. Many investigators believe he was into a cult. There are many theories about it. In this interview he even states he was into satanism and a man named Clark interrupts him to clarify "he was alone" its almost a joke

https://www.google.com/amp/s/www.cbsnews.com/amp/news/son-of-sam-serial-killer-david-berkowitz-speaks-out-40-years-after-new-york-city-murder-spree/

This relates to pizzagate because it explains there is a satanic cult inside the government which uses pedophilia, cannibalism and mind control programs to create havoc-slaves