Hangman of Darkness Book by Josh Cuny

When two young siblings' parents are murdered by a mysterious entity later known as The Hangman in 1840 in a rural area of Indiana, the brother and sister, Jacob and Luann must learn to take care of each other. Decades later in post Civil War Texas in 1870. Jacob and Luann reunite, only to have their joyful reunion cut short as the Hangman, who was responsible for their parents' murder returns. The two siblings along with others in the Texas town of Los Verdes must make a stand and get justice for their parents.