Yes and there was also a Governemnt Contractor Aaron Alexis who shot and killed 12 people at a Naval yard in 2013:
The government contractor who killed 12 people at the Washington Navy Yard last week was driven by delusions that he was being controlled by low-frequency radio waves and scratched the words End the torment! on the barrel of the shotgun he used, the FBI said Wednesday, offering new, chilling details of the attack.”
What wuz the frequency, Kennith?