Just before Christmas, Robert F. Kennedy Jr. pulled up to the massive Richard J. Donovan Correctional Facility, a California state prison complex in the desert outside San Diego that holds nearly 4,000 inmates. Kennedy was there to visit Sirhan B. Sirhan, the man convicted of killing his father, Sen. Robert F. Kennedy, nearly 50 years ago.

While his wife, the actress Cheryl Hines, waited in the car, Kennedy met with Sirhan for three hours, he revealed to The Washington Post last week. It was the culmination of months of research by Kennedy into the assassination, including speaking with witnesses and reading the autopsy and police reports.

“I got to a place where I had to see Sirhan,” Kennedy said. He would not discuss the specifics of their conversation. But when it was over, Kennedy had joined those who believe there was a second gunman, and that it was not Sirhan who killed his father.