TYLER, Texas — A Texas nurse has been convicted of capital murder in the deaths of four patients who died after prosecutors say he injected them with air following heart surgeries.

The Smith County jury deliberated for about an hour Tuesday before it convicted William George Davis, of Hallsville, of capital murder involving multiple victims.

Prosecutors plan to seek the death penalty during the sentencing phase, which starts Wednesday.

Prosecutors say the 37-year-old Davis injected air into the four patients' arteries after they underwent heart surgery at the Christus Trinity Mother Frances Hospital in Tyler in 2017 and 2018.

According to the Tyler Morning Telegraph, Davis was found guilty in connection with the death of patients John Lafferty, Ronald Clark, Christopher Greenaway and Joseph Kalina. All four suffered unexplained neurological problems while recovering from their surgeries and died.

During closing arguments, prosecutors alleged that Davis enjoyed the act of killing patients.

"He enjoyed going into the room and injecting people with air," Smith County First Assistant District Attorney Chris Gatewood said, according to Morning Telegraph.

Davis' lawyer says he is being scapegoated by the hospital.

The defense claimed that the patients who died had a history of strokes and prior health issues that could have led to their deaths and that Davis attempted to deliver life-saving measures to two patients.