The Law of the Land by Fred M. White

For one hour by the clock Ralph sat in his bedroom deeply immersed in his own painful thoughts. Try as he would, it was impossible to extract much consolation from Dick's cryptic utterances. Stephen Holt was dead, and he had killed him. And Barca knew all about it. Barca had adapted the whole, scheme to his own advantage, as he always did.

Perhaps that clever scoundrel had actually seen the crime committed.