Malcolm was gunned down on stage at New York's Audubon Ballroom while preparing to deliver a speech during an Organization of Afro-American Unity meeting by three men, fatally suffering 21 shots.
In the front row, a pregnant Shabazz shielded her four children. Malcom was 39.
While three members of the Nation of Islam were arrested for his 1965 murder, more than 50 years later, mystery still surrounds who really killed the civil rights activist.
Now 56 years later members of Malcolm X's family have made public what they described as a letter written by a deceased police officer stating that the New York Police Department and FBI were behind the 1965 killing of the famed Black activist and civil rights advocate.
The letter released at a news conference on Saturday was attributed to a former undercover NYPD officer named Raymond Wood. His cousin Reggie Wood joined some of Malcolm X's daughters at the news conference at the site where the Audubon Ballroom once stood to make the letter public.
Raymond Wood's letter stated that he had been pressured by his NYPD supervisors to lure two members of Malcolm X's security detail into committing crimes that resulted in their arrest just days before the fatal shooting. Those arrests kept the two men from managing door security at the ballroom and was part of conspiracy between the NYPD and FBI to have Malcolm killed, according to the letter.