Lee Harvey Oswald left his wedding ring in a cup on the dressing table and 170 dollars in one of its drawers before heading for work at the Texas School Book Depository - and an infamous place in world history.
Now the gold band that belonged to the man who assassinated John F Kennedy later that day, November 22 1963, is among nearly 300 items linked to the former US president that go up for auction in Boston today.
Bobby Livingston, an executive vice president with New Hampshire-based RR Auction, described the ring, which has a tiny hammer and sickle engraved on the inside of the band, as a "very powerful, significant piece of evidence".
"It gives you such insight into the mind of Lee Harvey Oswald," said Mr Livingston, who added that the ring could bring 100,000 dollars (£62,000) or more.
It was relatively recently that the seller, Oswald's widow, Marina Oswald Porter, recovered the ring, which apparently sat forgotten for decades in the files of a Fort Worth lawyer who once did work for her.
With the 50th anniversary of President Kennedy's assassination in central Dallas next month, the auction house has gathered items ranging from Kennedy's rosary beads and clothing items to Oswald's US Marine Corps rifle score book and a hat worn by Jack Ruby, the nightclub owner who killed Oswald two days after Kennedy's assassination.
Accompanying the ring is a five-page handwritten letter dated May 5 2013, in which Ms Porter writes: "At this time of my life I don't wish to have Lee's ring in my possession because symbolically I want to let go of my past that is connecting with November 22, 1963."
At her request, the auction house is not releasing the full contents of the letter, in which Ms Porter documents the history of the ring, from its purchase in the Soviet city of Minsk, Belarus, before their April, 30 1961 wedding, to how it was left on the dresser at her friend Ruth Paine's home, where she and their children were living when President Kennedy was killed.
Oswald, who lived during the week in a rooming house near central Dallas, usually visited only at the weekend.
The ring took a circuitous route from the dresser to being offered at auction. In 2004 it was discovered in the files of the lawyer who once worked for Ms Porter. It was in an envelope marked "Treasury Department Secret Service" with a receipt stating that Ms Paine gave it to the Secret Service on December 2 1963.
A July 2012 letter from the Fort Worth law firm of Brackett & Ellis to Ms Porter says the ring had apparently been in lawyer Forrest Markward's possession since 1964.
Luke Ellis, a partner at the firm, said when the ring was discovered, retired Mr Markward could not recall exactly how it cameinto his possession. Mr Markward has since died.
Also up for auction today are a white Lincoln Continental in which the president and first lady rode hours before his death and the sixth-floor window believed to have served as Oswald's sniper perch, which the building's owner removed in the weeks after the attack.