Atlanta shooting suspect due for first court appearance: here's what we know

 The suspect in a Wednesday mass shooting that killed one person and injured four others at an Atlanta hospital is expected to make his first court appearance Thursday morning.

Deion Patterson, 24, faces one count of murder and four counts of aggravated assault after he was accused of opening fire in the waiting room of a hospital in midtown, Atlanta, before allegedly carjacking a vehicle and fleeing, authorities said. He was arrested Wednesday evening after an hourslong search.

Patterson is scheduled to appear before a Fulton County judge at 11 a.m. Thursday.

What to know about suspect in midtown Atlanta shooting

The suspect was discharged from active duty in the U.S. Coast Guard in January after joining in 2018, according to a statement from the branch.

Police said his mother accompanied him to the hospital at the time of the shooting. Her son had an appointment at the hospital.

She told the Associated Press that her son had "some mental instability going on" possibly related to medication he received from the Veterans Affairs health system that he began taking Friday. She did not say what medication her son was taking.

How shooting unfolded in Atlanta hospital

Just after noon Wednesday, police received reports of shots fired on the 11th floor of Northside Hospital's Midtown location, Atlanta Police Chief Darin Schierbaum said.

After opening fire in the hospital's waiting area, Patterson exited the building after and fled on foot to a nearby gas station, where he carjacked a pickup truck and left the area, Atlanta Deputy Chief of Investigations Charles Hampton said.

Authorities later found the truck and recovered the handgun they say Patterson used in the shooting.

Arrest follows hourslong search as Midtown Atlanta froze

The arrest followed a nearly eight-hour, "chaotic" search that included several agencies such as Atlanta and Cobb County police, the FBI ad the U.S. Secret Service. Tips from community members and information from Patterson's family members were integral in the search, officials said.

Roughly 20 minutes after Patterson fled, license plate-surveilling cameras picked up the pickup truck's tag number, and law enforcement were alerted the suspect was in Cobb County, just northwest of Atlanta, Cobb County Police Chief Stuart VanHoozer said.

"Technology played a huge role," VanHoozer said. "But technology doesn’t do any good without people who are determined to capture an individual that would do something like this. And today we saw where those two things came together."

During the search, police issued a shelter-in-place advisory for midtown Atlanta, and several Atlanta Public Schools locked down. Northside Hospital said it would be closed on Thursday, and all appointments were canceled.

Victims include CDC employee; 3 women in critical condition

Amy St. Pierre, a 39-year-old employee with the Centers for Disease Control and Prevention, was identified as the woman killed in the shooting. According to a public LinkedIn profile, St. Pierre worked as a public health adviser for the CDC.

Four injured women – ages 71, 56, 39 and 25 – were hospitalized. Three of the four women were in critical condition from gunshot wounds Wednesday, and one was stable, said Robert Jansen, chief medical officer at Grady Health System, in an afternoon news conference.

It was not immediately clear if the victims were patients or staff.

Contributing: The Associated Press; Grace Hauck and Jeanine Santucci, USA TODAY