Yee said he had received death threats before but nothing as chilling as the lengthly email, allegedly sent by Everett Basham, 45, of Santa Clara, who was arrested Tuesday on multiple charges.
"The author of that email specifically stated that if I did not cease efforts to deal with gun violence that he would assassinate me in or around the Capitol," Yee said during a news conference Thursday. "He stated that he was a trained sniper."
Yee said he notified authorities about the note, which was several-hundred words long and detailed what weapons would be used to kill him.
The Los Angeles Times said Basham is an engineer and once worked with Apple Inc. co-founder Steve Wozniak.
Police said they found several weapons and chemicals that could be used in making bombs at Basham's home in Santa Clara.
Notable deaths of 2014 [PHOTOS]