During a recent court case, Stacey Hayes' attorney said a court appointed psychiatrist deemed him incompetent to stand trial.
His case is now on hold as Hayes undergoes mental health treatment.
Hayes, who was also a nursing assistant at Jefferson, is accused of walking into the hospital and opening fire on his coworker Anrae James on October 4.
James died a short time later at the hospital.
Police say Hayes was wearing scrubs and body armor, and carrying multiple weapons, including an AR-15 style rifle.
After the shooting, police say Hayes fled in a U-Haul truck, but was later spotted by officers in the city's Parkside section.
According to police, the officers ordered Hayes to "drop the gun" several times, but he ignored their verbal commands and discharged his rifle towards the officers. Four of the officers returned fire.
Two officers suffered non-life-threatening injuries after being struck by the gunfire.
SEE ALSO: Jefferson Hospital shooting suspect charged with murder, other crimes
Hayes was briefly hospitalized for his injuries.
His family told police he was recently suffering from mental health issues.
Sources say Hayes was known to police and had weapons taken away from him for psychiatric reasons. He petitioned the courts last year to get those weapons back and was successful.
Neighbors say Hayes was no longer living with his wife and children at their Parkside home; sources say he appeared to be living out of the U-Haul truck.
It's unclear when his trial will begin.