HOUSTON (AP) — Authorities say a 15-year-old boy fatally shot his 17-year-old sister and another teenage girl at a home near Houston this week before killing himself. Their bodies were found Tuesday in the home in rural area near Crosby, a community about 25 miles (40 kilometers) northeast of Houston. The Harris County sheriff’s office said Thursday that Hayden Burns fatally shot his sister, Haley Burns, and 17-year-old Kadience Cadena. It said Friday that investigators were still trying to establish a motive. Hayden Burns’ body was found in one bedroom and Cadena’s body was found in another. Haley Burns’ body was found in a hallway.