A veteran of the San Diego Police Department was stabbed to death in her own home alongside her teenage daughter, a recent high school graduate and talented athlete.

Residents of a Rancho Penasquitos neighborhood were awakened by screams Monday morning. Soon after, San Diego police officers discovered the bodies of Donna and Briana “Bree” Williams at a nearby home. Each woman had suffered numerous stab wounds.

The suspect, identified as Donna Williams‘ 24-year-old son, Brian Williams, was calmly sitting next to his dead sister in front of the home when police arrived. He did not resist arrest and did not appear to be under the influence of drugs or alcohol officials said.