"My plan was to kill my sister and my mom at my house and then go over to my grandparents and kill my oldest sister Emily and my two grandparents," wrote Evans, 17, in his confession to Parker County sheriff's investigators.
He is accused fo fatally shooting his mother, Jami, and 15-year-old sister, Mallory, last October. He has been jailed since then and was indicated in December.
"When I look at people, especially teenagers, I see them as being very cruel to one another emotionally," he wrote. "It seems that their favorite hobby is picking on someone else.
"I was very sad because I felt like my own family were [sic] becoming the people I hate."
The confession was released Thursday by Parker County court officials.