On a sunny October afternoon in 2018, a businessman driving through downtown Prince George, B.C., heard a woman screaming for help.

Two postal workers, picketing outside the post office during rotating strikes, also heard the cries.

The three men rushed over to help Diane Nakamura, a long-time social worker and Prince George finalist for Citizen of the Year.

She was lying on the sidewalk, robbed and knocked to the ground, suffering a brain injury that would end her career.

'I just wanted her bag'

The Good Samaritans tackled Nakamura's assailant, and held him down until the RCMP arrived and arrested him.

Marshall Schulze outside the Prince George courthouse after entering a guilty plea for one count of robbery. (Betsy Trumpener/CBC )

This week, in Prince George provincial court Marshall Schulze pleaded guilty to one count of robbery.

"I just wanted her bag," Schulze told the judge on Monday. "I was intoxicated on drugs. I took her bag forcibly."

Crown counsel told the court that in the struggle with Schulze, Nakamura was thrown down, struck the back of her head on the concrete and suffered permanent brain damage.

Brain injury ends career

That brain injury means Nakamura, who agreed to share her story with CBC News, can no longer work.

"I'm extremely fatigued," Nakamura said. "I sleep between 12 and 18 hours a day. I have no short term memory. I can't concentrate on stuff. I can't problem solve. So it's been a huge loss."

During her 33-year social work career, Nakamura supported the young victims of former judge David Ramsey , helping secure his conviction for sex crimes.

She also assisted the families of the victims of serial killer Cody Legebokoff .

Nakamura worked in Indigenous communities and government, as well as counselling people on the street, in jail, and in rehab.

She also helped clients like Schulze.

A robbery outside Prince George's downtown post office in 2018 left a renowned citizen with a permanent brain injury. Postal workers on the picket line came to her aid. (Betsy Trumpener/CBC )

"I find it quite ironic," said Nakamura. "I used to help people like him. Clients struggling with addictions and mental health ... I helped a lot of those folks."

Nakamura recalls Schulze being "visibly high on drugs" during the robbery. But as a seasoned social worker, that didn't scare her. "I thought, 'No. This is not your purse. You're not taking it.'"

Nakamura believes the crime she survived is a sign of the "deterioration of downtown."

"I never used to be scared about walking anywhere and now I am," said Nakamura. "This happened in broad daylight. You know this can happen anytime, anywhere," she said.

Schulze, who will be sentenced in May, has been released on bail and is currently living in Abbotsford while in rehabilitation. In 2013, he was convicted of drug trafficking and the illegal possession of several high-powered stun guns.

In Prince George court, Marschall Schulze pleaded guilty to one count of robbery. (Betsy Trumpener/CBC )

958 assaults last year

According to Prince George RCMP, police responded to 958 assault calls last year.

Superintendent Shaun Wright says social issues, including homelessness and drug use, are often to blame.

"I think there is a more visible, larger, and even perhaps slightly more aggressive element within the homeless population over the last couple years," Wright told CBC News late last year.