After his Oscar win for All the King's Men, Broderick Crawford found himself working out his Columbia contract in a string of rapidly deteriorating films. The Last Posse was a middling western, the sort that the studio sent out as bottom-of-bill attractions for their prestige pictures. The posse of the title, headed by sheriff Crawford, is a group of ostensibly honest townsfolk. When they catch up with the desperadoes who robbed a wealthy cattle baron, some of the posse members are overcome by greed and plot to keep the stolen loot for themselves. Once Crawford is wounded in a shootout, avarice prevails. There are no real winners at the end, as the remaining posse members straggle back to town, their heads hung in shame.
~ Hal Erickson, All Movie Guide