Iryna lived in a bomb shelter in war-torn Ukraine.

She fled with her mother, sister and brother to North Carolina in 2022.

Iryna's family says she built a new life in Charlotte, working full-time at a local pizzeria and going to community college to improve her English.

Iryna's obituary says she was a gifted and passionate artist.

She loved sculpting and designing unique, eclectic clothing that reflected her vibrant spirit.

She had a deep love for animals and often cared for her neighbors' pets.

Her family told officials she would not be buried in Ukraine, but the place she loved: America.

The train was pretty full.

When Iryna boarded the train, she sat in this aisle seat, in the row in front of him.

Brown was at the window.

Iryna was wearing headphones.

The two had no interaction whatsoever.

She was scrolling on her phone the entire ride.

They were together on the train for 4 and a half minutes.

Decarlos Brown showed little to no emotion on the ride.

He rested his head on the window.

About a minute before the fatal stabbing, we noticed a shift.

He started to fidget with his hand and his eyes widened.

This stood out because we knew what was about to happen, but it wasn't necessarily something that would seem strange or dangerous to you in the moment.

He actually rested his head on the glass again just seconds before he took a knife out of his pocket, stood up and immediately stabbed Iryna.

His charges include murder and committing an act causing death on a mass transportation system. That last charge means he could face the death penalty.

"Making it so no one can ride the train or is too scared to ride the train, is about the same threat. It's a terroristic act to make people afraid to go about their daily lives," U.S. Attorney Russ Ferguson told Channel 9.

When police revealed Brown's name, Channel 9 started digging into his criminal history.

We learned Brown has been arrested at least 14 times, and he's served time in North Carolina prison.

The most recent arrest before the attack was in January.

Those court records detailed concerns about his mental capacity.

His mother told us directly: he lives with schizophrenia.

Decarlos Brown had been arrested multiple times, according to court records obtained by Channel 9.

After Iryna's murder, Brown was booked into custody and held without bond.

But his mother told Channel 9 that she thinks her son fell through the cracks of a broken system.

In 2020, he was released from prison after serving the majority of an 8-year sentence for robbery with a dangerous weapon. His mother told ABC News that he wasn't the same after that prison sentence.

Brown's mother told ABC News that Brown would become "very irritated at small things" and would "get in trouble in the streets, get in fights with people in the neighborhood."

At one point after he returned home from prison, Brown was diagnosed with schizophrenia. His mother says he refused to take his medicine. When a mental health hospital turned them down for lack of space, Brown was taken to a shelter. Eventually, he ended up on the streets.

Brown's sister says he attacked her in 2022, and police arrested him. But she says she dropped the charges out of concern for her brother's mental health.

Brown's sister told CNN she talked to him after Iryna's death.

She said he told her he stabbed Iryna "because she was reading his mind."

Before the attack, Brown was arrested in January for misusing the 911 system, saying that people were trying to control him. Magistrate Teresa Stokes was working that night, and she released him without bond after getting a written promise to appear.

It's not unusual to issue a no-cash bond for that type of misdemeanor charge, and a suspect would typically not be held in jail for that type of misdemeanor. In previous cases, Brown failed to appear in court, but it's unclear if Stokes has that information when she determined his bond in January.

Magistrates typically have little information about the person arrested in front of them. They rely heavily on what the arresting officer tells them. They should have access to the suspect's criminal record, but it's not likely they would have access to mental health history unless the arresting officer tells them that.

Some of the blame has fallen on Mecklenburg County District Attorney Spencer Merriweather and the court system.

Channel 9's Hunter Saenz spoke with the DA about the case, but also asked what many in the community have been asking: "What needs to be done to ensure this doesn't happen again?"

Merriweather told Saenz that he and his team aren’t focused on the noise, they are focused on the job at hand.

Even with Brown charged with a federal crime, his office will proceed with the first-degree murder case.

He also said the tragedy is personal to him as a member of this community and it's shaken him, too.

Merriweather talked about more mental health resources, and changes to the judicial system, which could keep repeat offenders behind bars, needs to be in place.

"A person, who is a repeat offender with a record like this, should he have been on the streets?" Saenz asked the DA.

"What we do to make sure people who are repeat offenders who have been charged with crimes, are not on the streets, is make sure we make use of sentence enhancements like our habitual statute that would make sure that people who are waiting for trial, we make use laws that I had a hand in helping to change like the Pretrial Integrity Act," Merriweather said. "The current design of our system calls on us to wait for the worst thing to happen before we address a public safety threat, and that has to be something that changes."

Merriweather says he believes magistrates should have more information than they currently do when determining bond when a suspect is brought to the jail.

Brown's attorney says he plans to ask that his competence be evaluated due to his mental health history. We don't know what approach Brown's lawyers will take.

Jim Cooney, an attorney not working on the case, told Channel 9 that an insanity defense is possible, but extraordinarily difficult, with only a handful of successful cases in the last 40 years in North Carolina.

Channel 9 has reported on the community's calls for safer experiences on CATS transportation for years. We've spoken to victims who have witnessed assaults and shootings on buses or near the light rail, and leaders have pushed for changes ever since CATS bus driver Ethan Rivera was shot while on the job in 2022.

We first asked CATS if Brown had a ticket to be on the light rail train when Iryna was killed. CATS said they believe he didn't have a ticket. Earlier this year, Channel 9's Joe Bruno reported extensively on the disconnect between fare enforcement on CATS' light rail trains and found that fare enforcement has dropped since it peaked in 2023.

Data obtained by Channel 9 this week shows that since 2020, the Charlotte-Mecklenburg Police Department has responded to 23 different incidents involving assault with a deadly weapon or homicide on the CATS light rail.

Just days after Iryna's killing, Channel 9's Hunter Saenz spoke with three men whose job it is to run Charlotte's light rail safely: Brent Cagle, interim CEO for CATS; Eric Osnes, chief safety and security officer for CATS; and Lee Ratliff, assistant chief for Professional Security Services, the company that CATS contracts with to keep the transit system safe.
They called the stabbing a horrific event, a random act, and something that couldn't have been prevented from a law enforcement perspective. We asked if there was a security failure on board.

"I think that while the outcome is horrific, it's terrible, the system, the processes, they all functioned as they should have on that night,” Cagle said.

Cagle pointed to "other opportunities" for Brown to get help so that he wouldn't have been on the train that night. But he said he believes "processes worked."

We asked CATS leaders if a guard on board may have caused Brown to think twice before he did what he did.

Ratliff said he can't put a police officer or security officer on every street or bus.

"The perception of having security and presence is always great, and we want to increase those numbers, right? But at the end of the day, if someone wants to commit a violent crime, and that crime can be done in seconds ... there's nothing that a police officer can do to stop that act from happening," Ratliff said.

"We can react to it, but to prevent it, it's not a lot we can do."

As Decarlos Brown awaits trial for first-degree murder, many eyes are on Charlotte's response to the killing.

While changes from the state level may take more time, Mayor Vi Lyles says the city is now taking action. CATS security personnel will be redeployed to the Blue Line to increase fare enforcement. Lyles said that CMPD officers would also increase patrols in areas across the transit system, and that CATS would roll out new safety operations over the next two to three weeks.

Merriweather told Channel 9 he wants to give magistrates access to make more informed decisions when deciding on bail for accused criminals.

Local leaders say they want to work with the Federal Transit Adminsitration to improve safety and secure growth for Mecklenburg County's proposed transit plan.

Iryna's family wants privacy and peace as they mourn the loss of a young woman who escaped from war, only to become the victim of a heinous attack.

They're asking for people to not share the video of Iryna's death.

Channel 9 is committed to staying on top of the case and the developments.

Watch our full special, 9 Investigates: Light Rail Stabbing, below.