The justice department on Tuesday charged a man accused of fatally stabbing a Ukrainian refugee on a North Carolina commuter train last month with a federal crime that could carry the death penalty.

The federal charge comes amid growing questions about why Decarlos Brown Jr was on the street despite 14 prior criminal arrests before he was accused of pulling out a knife and killing 23-year-old Iryna Zarutska in an apparently random attack captured on video.

The case has become latest flashpoint in the debate over whether cities such as Charlotte are adequately addressing violent crime, mental illness and transit safety. The Trump administration says the killing shows how local leaders, judges and policies in Democratic-led cities are failing to protect their residents from violent crime.

“Iryna Zarutska was a young woman living the American dream – her horrific murder is a direct result of failed soft-on-crime policies that put criminals before innocent people,” the US attorney general, Pam Bondi, said in a statement. “We will seek the maximum penalty for this unforgivable act of violence – he will never again see the light of day as a free man.”

Zarutska had been living in a bomb shelter in Ukraine before coming to to the US to escape the war, according to relatives, who described her as determined to build a safer life.

Video released on Friday shows Zarutska entering a light-rail train on 22 August and taking a seat in front of Brown, who was seated behind her. Minutes later, without any apparent interaction, he pulled out a pocketknife, stood and slashed her in the neck, investigators said. Passengers screamed and scattered as she collapsed.

He was charged federally with causing death on a mass transportation system, which carries up to life in prison or the death penalty. Russ Ferguson, the US attorney for the western district of North Carolina, said additional charges could be brought as the investigation continues.

The federal case will run parallel with the state case charging Brown with first-degree murder.

The death penalty is also a potential punishment for people convicted of first-degree murder in North Carolina. However, the state has not carried out an execution since 2006. Legal challenges over the use of lethal injection drugs and a doctor’s presence at executions have in part delayed action.

Brown had cycled through the criminal justice system for more than a decade including serving five years for robbery with a dangerous weapon in Mecklenburg county, according to court records. He was arrested earlier this year after repeatedly calling 911 from a hospital, claiming people were trying to control him. A judge released him without bail.

His mother told local television she sought an involuntary psychiatric commitment this year after he became violent at home. Doctors diagnosed him with schizophrenia.

Court records show a judge ordered a psychological exam in July at the request of his public defender to determine whether he was capable of contributing to his own defense. It wasn’t clear if the exam was scheduled or why it didn’t happen before the late August attack.

The Mecklenburg county public defender’s office did not answer a call on Tuesday.

Charlotte has increased security along its transit lines in response to the fatal stabbing, mayor Vi Lyles said in a letter to the city’s residents. The Democratic mayor’s letter was also critical of the court system, echoing some of the critics of the city’s response.

Lyles called the killing “a tragic failure by the courts and magistrates”, saying the city’s officers arrest people who are then quickly released.

The stabbing comes as Lyles is seeking the Democratic nomination on Tuesday in her bid for a fifth term, and uproar from Republicans, including Trump and figures in the make America great again movement.

The state auditor, Republican Dave Boliek, said his office would audit Charlotte’s transit system, looking at its safety and security budget and private security contracts.

Strawweights Carol Foro and Shanelle Dyer kicked things off with a fight that brought Dana White into the Octagon to congratulate both athletes, with Foro coming away with the victory. From there, the finishes just started rolling, as Samuel Sanches stopped Chasen Blair and Freddy Vidal snatched a submission in the final minute of his fight with Felipe Franco before Lerryan Douglas detonated a left hook on the chin of Cam Teague. And then, to close out the night, Steven Asplund needed just 16 seconds to dispatch Anthony Guarascio to close out the evening.

After brief deliberations, White emerged to announce the new additions to the UFC roster, awarding contracts to both Foro and Dyer, Sanches, Douglas, and Asplund while also announcing that Vidal would get another opportunity to compete on the final episode of the season.