Muñiz Varela received his primary and secondary education in Puerto Rico and in 1973, he formed the Movimiento Socialista Popular, a university students pro-independence group.
[4] During this trip, Muñiz met Edith Cabrera, a divorced TV soap opera actress, and they were soon romantically involved, even though she knew that he was married.
In a court-ordered deposition,[6] Cabrera acknowledged their romance lasted until his death and that Muñiz had proposed marriage to her since he was separated from his wife Pilar Perez Negron.
Two weeks before his death, Muñiz called Cabrera from Havana and asked her to take petty cash from the travel agency and rent a furnished studio apartment for him in the Villamar neighborhood of Isla Verde.
Muñiz Varela was murdered on April 28, 1979, as he was driving to his mother's house in Guaynabo, a city that borders Bayamon, San Juan and Caguas.
A local Puerto Rican newspaper, the PNP backed "La Crónica", declared Muñiz Varela to be a drug-dealing communist in April 1984.