Two children of the late Robert F. Kennedy spoke in Dallas at the start of a year of observances for the 50th anniversary of the assassination of President John F. Kennedy.

Robert F. Kennedy Jr. and his sister, Rory, were interviewed Friday night in front of an audience in downtown Dallas.

Kennedy said his father spent a year trying to come to grips with his brother's death after the assassination.

Kennedy said his father believed the Warren Commission report, which concluded that Lee Harvey Oswald acted alone in killing the president, was a "shoddy piece of craftsmanship."

President Kennedy was assassinated in Dallas on Nov. 22, 1963. Senator Robert F. Kennedy was assassinated five years later at the Ambassador Hotel in Los Angeles.