I don't understand Chesterton

I mentioned in my December reading post that I had listened to an audio version of The Man Who Knew Too Much by G. K. Chesterton. The book is a series of short stories which revolve around Horn Fisher, who says about himself that he Knows Too Much.

Nearly every story involves a murder. And nearly every murderer gets away. Mr. "Knows Too Much" Fisher usually knows who committed the crime, but whether through lack of proof or some other reason, the murderer is not brought to justice in any traditional sense--such as being arrested and tried for the crimes committed. The usual explanation for nothing to be done about apprehending the criminal (because that's how I see them) is that they serve some greater purpose in the government, or the victim was a scoundrel, or...something. I think the one that bothered me the most was the policemen who was simply "retired" (with his pension!) after shooting two fellow-officers, both of whom died. Of course, he was shot, himself, but he recovered and lived and did not answer for his crime. The political reasons for that (having something to do with Ireland and England) weren't clear to me.

A few of the murderers end up dying one way or another, but none of them are apprehended or charged.

And I don't understand why. I don't understand what Chesterton is doing, or what this book is trying to say. It does not feel like any kind of ordinary crime or mystery novel to me.

I have been very slowly reading some of the Father Brown stories by Chesterton, and I am similarly at sea with them.

I have respected friends who love Chesterton, and he certainly engages my mind, but my heart is not with him. If anyone can shed some light on this, I'd be interested to hear your thoughts on Chesterton. What does he have against criminals, even if they happen to be important and influential people, paying for their crimes?