Yes, There is a CIA Heart Attack Gun - A 1975 Congressional Hearing Confirmed it In 1975 a congressional hearing revealed the CIA had numerous top-secret weapons including a gun that became known as the “CIA heart attack gun.” In 1975 Congress investigated the CIA out of concern that former President Nixon may have used the CIA in an abuse of his powers. Nixon had resigned from office the previous year on August 9, 1974, fearing impeachment amidst the Watergate scandal. One revelation from the Congressional hearings was that the CIA had a secret assassination weapon otherwise known as the “heart attack gun”. According to a video interview with Mary Embree, a former CIA employee, she was asked to help develop an “ice gun”. The CIA asked her to help find a poison which when administered would mimic a heart attack in a person but remain undetectable.