NBC Story here:
https://www.nbcnews.com/news/us-news/robert-f-kennedy-assassin-sirhan-sirhan-stabbed-prison-n1048556
He said the person, whose identity he could not release, was taken by ambulance to a hospital shortly before 2:50 p.m.
Sirhan has been in the state's prison system since May 1969, nearly a year after Robert Kennedy, who was seeking the Democratic nomination for president, was assassinated.
Kennedy was shot and gravely wounded after midnight June 5, 1968, after a speaking to supporters at the Ambassador Hotel in Los Angeles
