Interesting, because I get conflicting stories. First I hear that the Secret Service canceled Kennedy's trip to Chicago in fear for his life however, Congressman Donald Irwin says that Jack went to Chicago and left the same evening he arrived due to a cold. By the way, I've never heard about a four man sniper team in Chicago, but I did hear about a plot to bomb Jack Kennedy's car along with mayor High in Miami, but that was called off when 250 additional police were added to the force without Kennedy's knowledge.
The plot in New York was in my opinion no different than Chicago, Tampa or Miami the plot was never carried out until Dallas.
I had a feeling his name would come up, the best way I know how to describe Vallee, was someone with some serious mental issues who was seriously looking for attention, the attach document says he was arrested by Chacigo police on hearsay, planning on starting some trouble during Kennedy's visit, there is no report of Vallee threatening Kennedy's life, or is there any information regarding an assassination plot, unless, Vallee went up to Abraham Bolden and specifically told Bolden he was going to shoot Jack, I doubt that happen.
Again, I've never heard of any four man assassin team in Chicago plotting to kill Jack, I'm pretty sure that someone created that story.