Texas Nurse William George Davis killing John Lafferty, Ronald Clark and Joseph Kalina

A Texas nurse who was convicted of capital murder for injecting four men with air has been sentenced to death.

A Texas nurse has been convicted of capital murder in connection with the deaths of four men who were purposefully injected with air following heart surgery.

On Tuesday, the Smith County jury debated for approximately an hour before returning a guilty judgment for William George Davis. Prosecutors have stated that they will seek the death sentence during Wednesday's sentencing phase.

Davis was charged with pumping air into four separate patients — John Lafferty, Ronald Clark, Christopher Greenway, and Joseph Kalina — while they were recovering at Christus Trinity Mother Frances Hospital in Tyler in 2017 and 2018. As a result, despite being in stable condition immediately following their operations, all of the men developed deadly but unexplained neurological symptoms.

During Davis' trial, Dr. William Yarbrough, a pulmonologist and professor of internal medicine in the Dallas region, explained to the jury how such an injection into the brain's vascular system can result in brain injury and death. He highlighted that he was able to establish the presence of air in the victims' brains' vascular system by examining scan photos - something he claimed he had never seen before in his decades in medicine.

Davis was on duty at the time each of the men died. Throughout the trial, his attorney, Phillip Hayes, dismissed it as coincidental, contending that his client was just in the wrong location at the wrong time.

Hayes stated that the hospital was making a scapegoat out of the former nurse for the deaths.

During his final remarks, prosecutor Chris Gatewood instead contended that Davis "loved to kill people."

Texas Nurse William George Davis killing John Lafferty, Ronald Clark and Joseph Kalina
William George Davis, charged with capital murder, listens to closing arguments in court Tuesday, Oct. 19, 2021, in Tyler, Texas, as he awaits trial for the 2017 and 2018 deaths of four patients at Christus Trinity Mother Frances Hospital in Tyler.