Kao Xiong apparently had a thing for letter writing, mailing out more than 150 letters since January 2017 to President Trump, former presidents, an FBI agent, Dallas/Fort Worth International Airport and a number of individuals.
The letters from Xiong, a 34-year-old Oroville man, contained a number of death threats, bomb threats and extortion demands, as well as references to a group he called the ‘Unstoppable Force,’” federal court records say.
“Pipe Bomb, Everyone is going to die,” one letter sent to DFW offices in Texas read, according to court records.
That letter and dozens of others, some containing white powder later determined to be flour, prompted “expenditure of significant taxpayer dollars” and hazardous materials response by officials trained in handling weapons of mass destruction, according to a criminal complaint filed under seal against Xiong in December 2017.
On Thursday, Xiong appeared in a federal courtroom in Sacramento and pleaded guilty to a single count of using the mail to convey a malicious threat about an explosive device, an offense that carries a maximum prison term of 10 years.
There is no evidence that Xiong ever built any device, and he told investigators he had no access to explosives training or any intent to hurt anyone. He was allowed Thursday to remain out of custody pending sentencing in March under a plea agreement.
Xiong’s federal defender, Tim Zindel, described the case after court as “just a touch of mental illness,” and Xiong, a former Amazon worker, conceded in court that he had previously been treated for mental illness.
Court documents describe a somewhat unrelenting penchant for mailing hoax threat letters, even after he was questioned in separate interviews by the Secret Service and an FBI agent.
“Hoax/threat letters continued to be mailed after each of the interviews,” court documents say. “Xiong’s behavior escalated after the FBI interviewed Xiong in that some of the letters included the name and work address of the interviewing agent ... who had provided Xiong with his business card.”
Letters went to former Presidents George W. Bush, Barack Obama and Ronald Reagan (who had been dead for 13 years at the time), as well as the Mall of America and the headquarters of Yahoo.
Two identical letters sent in November 2017 to Hmong TV in Minnesota and the FBI’s Boston field office demanded a $1 million payment be dropped off at a McDonalds in Lyndale, Minn., court records say.
“I need one million dollars or Donald Trump is dead,” the letters declared.
The Xiong case preceded a string of mail bomb packages sent in the fall to critics of President Trump and Democratic politicians that shut down neighborhoods and post offices as the packages made their way through the mail nationwide.
One of the devices was addressed to U.S. Sen. Kamala Harris, D-Calif., and was discovered in a Sacramento post office in October, where authorities spent five hours before declaring the area safe. Federal authorities later charged a Florida man, Cesar Sayoc, in that case.