Which Way Tree by Elizabeth Crook
This is a Texas western adventure story, told by 17 year old Benjamin in a series of letters to a traveling judge as his testimony as a witness to the murder of eight people. Years earlier Benjamin and his half sister, Samantha, went on a dogged pursuit of a demon panther who scarred Samantha and took her mother's life. They meet up with some characters along the way, some good and one very bad. I recommend this book. The western is not dead!