Boston Celtics guard Jabari Bird was already facing assault and battery charges after allegedly repeatedly choking and beating his then-girlfriend in his Massachusetts apartment on September 7, and on Wednesday prosecutors added two additional charges: threats and witness intimidation.

The alleged victim told police she escaped when Bird experienced seizure-like symptoms.

'If you don't stop talking I'm going to kill you,' the victim alleges Bird said, according to court docs obtained by TMZ.

She also claims Bird told her: 'Tell anyone about this, I don't care where you are, I'll find you and I'll kill you.'

Bird, who is due back in Brighton Municipal Court next month, has maintained his innocence after previously pleading 'not guilty' back in September.

Boston Celtics reserve guard Jabari Bird leaves the courtroom at Brighton Municipal Court in Boston after appearing to face new charges connected to a reported act of domestic violence in September on Wednesday. The 24-year old maintains his innocence

'I'm taking some time away from the team as I deal with my legal and medical issues. I apologize to my family, the Celtics organization, my teammates, the fans and the NBA for the unnecessary distraction that I have caused,' Bird wrote in a September statement.

'The information that has been released does not tell the full story. I do not condone violence against women. I am hopeful that in due time and process, I will be able to regain everyone's trust.'

Bird, 24, choked the woman unconscious, threw her against the wall and dragged her by the ankles when she tried to leave his apartment in the Brighton neighborhood, police said.

Jabair Bird, a second-round draft choice of the Celtics in 2017 , signed a two-year contract with the team in 2018 after splitting his rookie season between Boston and the Maine Red Claws of the G-League. The Celtics would have to pay Bird his entire $1.5 million salary for the year if they were to release him before the NBA finishes its investigation

The ordeal, sparked by what the woman called 'trust issues,' went on for several hours, she said, until Bird experienced 'seizure-like' symptoms and fell. That's when the woman left.

Bird spent several days in a hospital.

Bird's lawyer, former federal prosecutor Brian Kelly, said that his client 'understands the seriousness of the allegations' but that there are two sides to the story.

In September, the Celtics called the allegations disturbing and said the team's 'thoughts are with the victim.'

'Pursuant to Domestic Violence Policy in the NBA's labor agreement, matters of this kind are handled by the League Office, not the team, and so the Celtics will be working with both the league and local authorities to assist in their ongoing investigations,' a Celtics spokesperson explained in a statement.

The Celtics would have to pay Bird his entire $1.5 million salary for the year if they were to release him before the NBA finishes its investigation.

Bird, a second-round draft choice of the Celtics in 2017 out of California, signed a two-year contract with the team this summer after splitting his rookie season between Boston and the Maine Red Claws of the G-League. He appeared in 13 regular-season games for the Celtics last season, averaging 3 points per game.

A college teammate of Celtics star Jaylen Brown's at the University of California, the Bay-area native averaged double figures in scoring in each of his four seasons with the Golden Bears.