(CNN) — An eight-hour manhunt that threw a major American city into fear and chaos ended when barking dogs at a suburban condo complex led to the arrest of a US Coast Guard veteran suspected of fatally shooting a woman and injuring four in a medical waiting room in the bustling heart of Atlanta, authorities said.

The suspect, Deion Duwane Patterson, 24, faces one count of murder and four counts of aggravated assault, Fulton County jail records show. Patterson waived his right to a first appearance in court, which had been set for Thursday morning, the jail supervisor said.

Now, as a community mourns the loss of a beloved health worker in a place traditionally considered safe, the suspect’s mother is apologizing to the families of those slain and hurt. She also has a message for anyone asked to help someone with mental illness: “Don’t disregard them.”

“I’m trying to advocate for my son,” Minyone Patterson said, according to CNN affiliate WANF. “Just be careful.”

Deion Patterson had sought treatment around noon Wednesday at the Northside Medical Midtown facility because he was dissatisfied with care he was getting from the Department of Veterans Affairs, his mother told investigators, according to a high-level source with the Atlanta Police Department.

But when doctors wouldn’t give him the anti-anxiety drug Ativan, Patterson got angry, his mother told CNN affiliate WSB. He pulled a handgun and began firing, the source told CNN, then took off on foot, stole a vacant pickup truck idling at a gas station and drove it north to Cobb County.

With schools and businesses on lockdown for miles around, police drew on camera technology systems and information from Patterson’s family to blanket the zone, finally getting a tip that spurred an undercover officer into a foot chase with the suspect Wednesday night at the gated complex, Cobb County Police Chief Stuart VanHoozer said.

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

The attack marked one of 192 mass shootings this year in the United States with four or more people shot, excluding a gunman, according to the Gun Violence Archive. Federal health worker Amy St. Pierre, 38, died on the scene, the Fulton County medical examiner’s office said, as four other injured women were rushed to a nearby hospital, according to police.

“This kind of thing is happening every day. Some day it will touch you in some way,” said Neal Cohen, a longtime friend of the slain victim. “Tragically, today it directly touched my life. And I am still attempting to process the loss of my friend Amy.”

Atlanta Mayor Andre Dickens condemned the attack as “a horrible act of gun violence.”

“Equally horrifying is that we know that this is not unique in our country,” the Democrat said in a news conference. “There’s a lot of talk about Second Amendment rights. … We need more actions about the rights of our citizens to go about their lives — to be able to go to a doctor’s office, to a supermarket, to a gas station or to their school without the threat of being gunned down.”

Suspect’s mother apologizes and gives a warning

The suspect served with the Coast Guard from 2018 until his discharge in January, the military branch said. CNN has reached out to the VA for comment.

Patterson was “always a protector. No one that would hurt anybody,” his mother Minyone Patterson said, according to WANF. “And even in his time of need, he was still trying to help others. That’s just the person he’s always been.”

But the young man also struggled, she in her apology after the mass shooting.

“First and foremost, I want to give my sincere, sincere apology to the families that were injured and killed,” Minyone Patterson said, according to WANF. “This mental illness is real, and when we say it’s real, from the medical standpoint, it is real.”

“And when someone is saying they need help, or you see that they are acting out of sorts, they need help,” she said. “Help them, just don’t disregard them. They need help.”

How the shooting rampage and manhunt unfolded

Shortly before noon, the gunman entered a medical facility in the building in Midtown Atlanta, said Charles Hampton, Atlanta police’s deputy chief of criminal investigations.

“It was shortly thereafter that he shot our first victim, and then the first 911 call came after that.”

Officers were called at 12:08 p.m. ET to the medical facility, Atlanta Police Department Chief Darin Schierbaum said.

Soon, an official shelter-in-place order beeped across the cell phone network, and an apartment building a block away went on lockdown.

From there, resident Annie Eaveson could see “medical professionals huddled up in offices” at the medical building on West Peachtree, one of dozens of city streets that famously share the arboreal moniker.

“I saw two people taken out on stretchers” she told CNN.

“Waves of armored officers went inside in shifts almost,” Eaveson said.

But the gunman was nowhere to be found.

Deion Patterson had fled the building on foot, quickly making his way to a nearby gas station, Hampton said.

There, a “camera network system” caught footage of the suspect stealing a pickup truck that had been left running and unattended, Hampton said. The truck’s tag was then submitted to a license plate reader system, he said.

At about 12:30 p.m., license plate readers spotted the truck in neighboring Cobb County, about 15 miles from the scene of the attack, the deputy chief said.

Cobb County officials were notified right away, Hampton said, and officers rushed to scour the area for the vehicle, said VanHoozer, the county police chief.

Suspect captured at a private condo complex

As the search stretched into the evening, Cobb County law enforcement got a wave of calls reporting possible sighting of the suspect — creating a “chaotic scene” as officers responded to several false alarms, VanHoozer said.

“These are massively complex investigations, and information comes in so quickly,” the chief said Wednesday night. “It is so confusing and so contradicting that we find that we are often trying to go three or four different places very quickly — each seeming to be the suspect.”

When Christy Colwell heard dogs barking in the Waterford Place complex where she lives, she worried the suspect could be hiding in the pool area, which includes a gazebo, she said,.

She informed police officer already there responding to a noise call.

“He just started running — the police officer — and said, ‘Get on the grass! Get on the grass!'” resident Debra Sansavieri said. “Suddenly about 30 police cars came flying down.”

A police crime center operator also alerted officers to a 911 call likely about the suspect, the chief said.

“We prioritized that call on the radio,” he said, adding both undercover and uniformed officers were sent to the scene.

“I believe … that an undercover officer was the one that originally saw and confronted this individual and was able to then have backup from uniformed officers that came in and took him into custody without incident,” VanHoozer said.

VanHoozer credited the successful capture in part to recent advances in police tracking technology.

“If you rewind the hand of time four years, we probably would not be where we are today, right now,” he said.

Survivors taken into surgery as CDC mourns colleague

St. Pierre, who was killed in the attack, worked for the Atlanta-based US Centers for Disease Control and Prevention, the agency confirmed to CNN. The CDC is “deeply saddened” by the loss, it said.

“Our hearts are with her family, friends, and colleagues as they remember her and grieve this tragic loss,” agency spokesperson Benjamin Haynes said.

Surviving victims were taken to the nearby Grady Memorial Hospital, Atlanta’s only Level 1 trauma center.

Three of the women arrived to the hospital in critical condition and had to have surgery, while the fourth was in stable condition, the hospital said in a statement.

One critical patient needed surgery for a gunshot wound to the abdomen and another for a wound to the arm, a hospital representative said. The third patient had suffered a gunshot wound to the face and required an interventional radiology procedure used to stop bleeding by inserting catheters directly into blood vessels, the hospital said.

They were recovering in the ICU as of Wednesday evening, the hospital statement said.

The stable victim will likely not need surgery, Grady Health System Chief Medical Officer Dr. Robert Jansen said in a news conference.