A man who murdered one woman and badly injured another during a stabbing rampage in Sydney’s CBD in 2019 has pleaded guilty.

Mert Ney was arrested in August 2019 after bystanders held him down with a chair and milk crate as they waited for police.

The 22-year-old was filmed running through the streets with a knife and yelling during the incident, which sent the heart of the city into lockdown.

Ney was charged with the murder of Michaela Dunn, 24, and the serious wounding of Lin Bo, who was 41 at the time.

Prosecutors and defence lawyers have been negotiating a plea deal since mid-September.

In Central Local Court, Ney pleaded guilty to murdering Ms Dunn, wounding Ms Bo and assaulting his sister.

Michaela Dunn’s body was found in a her Sydney apartment.

His lawyer Zemarai Khatiz told the court a charge of possessing drugs will be considered on sentence, while six other charges will be withdrawn.

Ney appeared via video link and spoke in a clear voice when asked how he would plead.

Ney visited Ms Dunn for a sex work appointment before she was killed, police said.

The plea deal comes after a magistrate expressed frustration with delays in the matter, including by Ney’s defence team who wanted more time to consult with a psychologist and obtain a report.

At least 1500 pages of material about Ney’s circumstances had already been produced from Justice Health and other organisations.

The court has previously heard Ney’s lawyers were considering raising his mental health and fitness to plead.

He has been medicated for pain and mental illness while in custody and experienced problems such as insomnia.

The case will return to court in December.