A ranking FBI official says authorities are pursuing a possible hate crime charge as well as a homicide charge against a white supremacist suspected of murdering a security officer at the U.S. Holocaust Memorial and Museum.

Joseph Persichini, assistant director of the Washington FBI field office, said authorities did not have an "open file" on the suspect, 88-year-old James von Brunn, a Holocaust denier. And Persichini stressed that the investigation into the slaying of 39-year-old guard Stephen Johns was still "in the preliminary stage."