(KSLA) - More charges could be filed against an East Texas nurse who was arrested Tuesday on a murder charge.
Authorities confirm there have been two deaths.
At present, 34-year-old Registered Nurse William George "Will" Davis, of Hallsville, Texas, faces the one charge in relation to the death of a 47-year-old man.
But multiple charges of aggravated assault may come later as a result of the ongoing investigation, Tyler, Texas, Police Chief Jimmy Toler said during a news conference Wednesday afternoon.
"We are currently investigating up to seven incidents at CHRISTUS" that have occurred since June, the police chief said.
Those cases involve seven adult patients, including a half dozen men and a woman.
KSLA News 12's Doug Warner confirmed Tuesday that Davis is the same man whose nursing license has been temporarily suspended by the Texas Board of Nursing.
Toler said Wednesday that their investigation of Davis began when CHRISTUS approached his department and the Smith County, Texas, district attorney's office early this year with concerns that a nurse may have been involved with intentionally causing harm to patients at one of their hospitals.
"These patients were experiencing unexplained symptoms inconsistent with their treatment and recovery."
"... I must conclude that these patients were intentionally injected with air through their radial artery lines by nurse William Davis. I can find no other logical explanation ... ," Dr. Kenneth Layton, head of Baylor University Medical Center's radiology department, says in a statement included in the arrest affidavit.
His comments were in response to a request for his opinion on cases involving three of the patients.
Following is another excerpt from the arrest affidavit:
The police chief said they never had another suspect.
"I will say that we only had one person of interest in this case. And that person is now in custody. ... And there's no reason for us to believe that there is anyone else associated with these injuries."
Court documents show the nursing board is investigating Davis for allegedly tampering with the welfare of at least three patients at a heart hospital in Tyler, Texas.
One of those patients died and the other two were left in vegetative states, according to the documents the board filed in Austin, Texas. Those documents show the three encounters happened in August, November and January at Louis & Peaches Owen Heart Hospital.
The nursing board took action in March.
And Tuesday evening, KSLA News 12 confirmed that Tyler, Texas, police arrested Davis on a charge of murder.
Online records show he was booked into the Smith County, Texas, Jail. His bond has been set at $2 million.
In each of the three cases before the nursing board, Davis is accused is having unauthorized access to a patient and performing unnecessary or inappropriate interventions on each patient.
In August, Davis' alleged inappropriate behavior caused an unidentified patient to have a stroke and die. Davis is accused of tampering with the patient's IV and failing to communicate his intervention with the patient.
The nursing board alleges that Davis did the same thing again in November, this time resulting in a patient having a stroke five minutes later. That patient, according to court documents, was left in a vegetative state.
And in January, Davis again was accused by the nursing board of entering a patient's room to whom he was not assigned and performing an unnecessary or inappropriate intervention with that person. According to those same documents, that patient also was left in a vegetative state.
CHRISTUS Mother Frances Hospital in Tyler fired Davis on Feb. 15 and turned its findings over to the state nursing board.