A transgender woman has been shot dead in public after an altercation in Portland, Oregon.

Gigi Pierce, 28, became the 11th trans person to be killed in the US this year when she died on May 21.

That number may yet rise when police determine the cause of death of 39-year-old Nicole Hall, whose body was found in White Rock Creek in Dallas, Texas, earlier this month.

Sophia Grace Adler, 33, was arrested at the scene in downtown Portland and later charged with murder.

She pleaded not guilty in court on Tuesday.

Pierce, from Boise in Idaho, was found lying wounded on the side of the street by emergency staff, but died within minutes of them getting to her, according to local TV channel KATU.

Those who knew her on the street have said that Pierce made it her mission to protect other homeless women.

Amber, a friend of Pierce, said she was present when the shooting happened.

“She died in my arms,” she said.

“I heard Gigi say: ‘Don’t touch me,’” added Amber. “And the woman came up and hit Gigi in the face with her purse.

“That kinda set Gigi off. Gigi went to hit her, pulled back to hit her, and the next thing I know my ear’s ringing.

“There had been a gunshot. It all happened so fast.

“It always does. It all happened so fast.”

Sergeant Chris Burley of the Portland City Police backed up this account.

He said: “We do believe that prior to the shooting there had been some type of disagreement or disturbance that was going on that led up to the shooting.”

Josie Deleon-Summa, who got to know both Pierce and her suspected killer, paid tribute to the victim.

“Gigi was the kind of person that was just full of life, always trying to help somebody,” said Deleon-Summa.

She added that if Adler did shoot her, it was out of character.

“Something happened last night to make her snap,” she said. “But she’s a good kid. Just misunderstood. I don’t know exactly what happened between the two.”

A total of 28 trans people were killed in the US in 2017, the highest number on record.

The current rate of trans killings in 2018 is the same as last year.

Nino Fortson, 36, died after being shot multiple times following an argument in Atlanta, Georgia during the early hours of May 13.