In the letter, the 42-year-old apologized for treating people "abusively" and wrote that he "used people for money" and "betrayed MANY people and much trust."
"I have come to some stark revelations about my character. You see, I believed myself to be a good guy. I HAVE NOT been a good guy. In fact, I have been a pretty bad guy throughout my life," he wrote.
"And while it's true I have outed many pedophiles that were former FRIENDS, I remained in their sphere for much longer than I should have, and attempted to gain from them AFTER I knew about their actions."
"To the MANY people I have acted abusively towards, I am very sorry. To my former friends I have used and betrayed, I am sorry. To those I have decided, I am sorry, although I must say, in my SHEER ARROGANCE, I did not even realize that I had been the bad actor all along," he wrote.
Kappy stated that he had been "lacking in gratitude, humility, honor, service, and proper care for others" and that he had not "honored the light of God within."
The Arizona Daily Sun reported that Kappy died Monday afternoon in Bellemont, Arizona after he jumped from the Transwestern Road bridge onto Interstate 40, where he was struck by a Ford pickup truck.
Throughout his career in Hollywood, which began with a role in the short film Star Down in 2006, he appeared in small roles in AMC's Breaking Bad as well as in the films Thor and Terminator Salvation. Kappy also wrote two short films, The Cougar and The Surrogate, and was the lead singer of the band Monster Paws. His latest acting role is credited as a 2016 episode of Rachel Dratch's Late Night Snack.
He was reportedly the subject of a police investigation last August after allegedly stalking and harassing Seth Green and his wife, Clare Grant, as well as accusing them of being pedophiles. TMZ reported last year that Kappy allegedly grabbed and choked 21-year-old Paris Jackson, the daughter of Michael Jackson, by the throat at a game night party.