Deputies were dispatched to the 900 block of Big Sky Drive after a 911 call reporting an unknown emergency at approximately 4:13 a.m. on October 1.

Inside the home, they found two victims with gunshot wounds. Christopher Scott Pitre, 21, of Waxahachie, was dead at the scene. His 15-year-old brother was taken to a local hospital in critical condition and later died.

Deputies also found the victims’ mother, Colleen Nichole Lemmon, 42, with injuries described as not life-threatening. Investigators said evidence recovered during the investigation gave them probable cause to believe she had shot both sons.

Lemmon was arrested and taken to a local hospital for treatment - Lemmon’s booking photo shows what appears to be a wound on the side of her neck. After her release, she was booked into the Wayne McCollum Detention Center on two counts of capital murder.

The sheriff’s office did not describe a possible motive or explain how Lemmon was injured.

The victims’ father has been notified of both deaths.