Pop. 1280 occupies a special place in Jim Thompson's catalog of novels. Like The Killer Inside Me, it is about a sheriff in a small town in Texas who convinces everyone he is a fool while cleverly manipulating criminals and upstanding citizens alike to keep the peace and make life as easy and enjoyable for himself as he can.
The two books are so similar it is tempting to think that when Thompson wrote Pop. 1280 in 1964, he was trying to repeat the success he had with The Killer Inside Me in 1952. Whether or not that was his motive, he accomplished much more. Pop. 1280 is a better novel.
Lou Ford, the sheriff in "Killer" is a psychopath. He is consistently cruel and profoundly unfeeling toward his fellow human beings. Many have remarked that Thompson's portrayal of this type of criminal is unequaled, perhaps because the story is narrated by him in the first person.
Nick Corey, the sheriff in Pop. 1280 is more complex. While capable of being cruel and manipulative, he has genuine feelings for the three women he visits for sex. He has a sense of justice and will do what he must to set things right in his town, even if that means breaking some rules. And he feels guilty when circumstances force him to hurt an innocent person.
Perhaps Thompson was able to treat this subject with greater nuance because by 1964, he was a more experienced writer and as a more mature man