On Wednesday, March 6, 2013, at approximately 4:15 p.m., the McKinney Police Department received a 911 call regarding an unknown medical problem at 306 Pintail Dr. According to the caller, a child came home and could not enter the front door. The child observed their mother through the window lying unconscious on the floor. The child alerted neighbors for help, who then called 911.

Once the first responders from the Police and Fire Departments were on scene, they could see the unresponsive woman on the floor. Due to the exigent circumstances, first responders forced entry to check on her welfare. Officers found Mary "Beth" Merz deceased near the front door from apparent gunshot wounds. After checking the residence, officer located one other person, identified as Eric Merz, lying on the floor in the study. He was unresponsive and transported to Baylor Medical Center at McKinney in stable condition.

Investigators obtained a search warrant for the residence and an arrest warrant for Eric Merz. Merz was taken into custody and later booked in at the Collin County Detention Center for Murder. His bond was set at $150,000.