Jerry Brown, the former Governor of California, is questioning the sale of memorabilia relating to the assassination of John F. Kennedy that once belonged to his deceased father. 

The memorabilia, including letters and correspondences from both JFK and Lyndon Johnson, is valued between $20,000 and $30,000 and is being auctioned by Sotheby's. The seller wishes to remain anonymous. 

The collection includes a series of letters and notes addressed to Brown's father, Pat Brown, who served as Governor of California between 1959 and 1967. 

One letter from Kennedy, ten days before his assassination, expresses gratitude to Brown for supporting his tax reform program. 

Another note, this time from Lyndon Johnson,  was delivered shortly after the infamous assassination and bore the message: "Pat I'm really depending on you in the west."

The collection also includes an original Associated Press wire announcing Kennedy's death which was delivered to Brown Snr. 

AP bulletin informing Pat Brown of JFK's assassination. Sotheby's

AP bulletin informing Pat Brown of JFK's assassination. Sotheby's

"President Kennedy was shot today just as his motorcade left downtown Dallas. Mrs. Kennedy jumped up and grabbed Mr. Kennedy. She cried, "Oh, No!" The motorcade sped on," the bulletin reads. 

But the younger Brown, who has served a record 16 years as Governor of the Golden State, claimed he had not been informed of the sale of the priceless papers. He also questioned why the seller wanted to remain anonymous. 

"I'd sure like to know why the seller is claiming anonymity and why these documents aren't at the UC Berkeley archives with the rest of my father's papers," Brown said in a statement to The Associated Press.

Sotheby's labels the collection unique since it "chronicles a country in mourning" and "comes from an original source." The auction is scheduled to start at 2 p.m. Eastern time on Monday afternoon. 

Ethan Rarick, who researched Pat Brown for his biography "California Rising," believes that the collection may come from somebody who worked in the Brown Administration. 

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Deputy Director of the  UC-Berkeley's Bancroft Library, Peter Hanff, echoed that theory and said that someone probably held onto the collection for "autograph value." He believes a collector would have more use for the memorabilia than a scholar. 

The collection is part of Sotheby's Americana sale, which includes a letter from John Hancock announcing the adoption of the Declaration of Independence, estimated to be worth over $800,000.