The federal government on Friday released the first tranche of approximately 50,000 pages of classified documents related to the investigation into the assassination of Robert F. Kennedy in 1968.

About 10,000 pages of records related to the 1968 assassination of Sen. Robert F. Kennedy were released Friday, including handwritten notes by the gunman, who said the Democratic presidential candidate “must be disposed of” and acknowledged an obsession with killing him.

The 1968 slaying was mainly investigated by the Los Angeles police, whose files were released in 1988, but the FBI and other federal agencies had related records.