Yesterday: Phillip Coleman in 1943, the last man hanged in Montana. He was executed for a vicious robbery-and-murder spree that left three people dead. Someone who knew more about the case than I said in the comments section that Coleman confessed 23 additional murders, but the confession has been lost and it isn’t known whether what he said was accurate or not.
Today: Meir Berliner and ten others at the Treblinka Extermination Camp in 1942. Berliner, a Jewish prisoner at the camp whose entire family had been gassed, murdered an officer in an act of suicidal revenge. He was killed for it, along with ten other inmates (and 150 more the next day) in the spirit of collective responsibility. But in an indirect a result of Berliner’s actions, a year later the inmates were able to launch a revolt and mass escape from the camp.