NEW YORK, USA (CMC) — Police here have testified that a Guyanese-born teenager in Brooklyn used her last few breaths to tell police the name of the man who shot her after she spurned his advances, as she struggled through an agonising 20-minute wait for an ambulance.

Sixteen-year-old Shemel Mercurius was fatally shot inside a Brooklyn apartment last year by a 25-year-old man who wanted to date her.

Earlier this week, at the trial of Taariq Stephens — who is charged with murdering Shemel — the Brooklyn Supreme Court heard from the hero patrol cop who tried to keep her alive.

The police reported that Shemel, a junior at Edward R Murrow High School in Brooklyn, was babysitting her three-year-old cousin on May 31, 2016, when Stephens allegedly showed up at the Brooklyn Ave apartment and shot her three times with a submachine gun.

Responding, New York Police Department (NYPD) officers kicked down the apartment door to find a horrifying scene.

“There was a three-year-old male child covered in blood crying next to the victim,” said Sgt Ryan Habermehl, who testified that he immediately called the Emergency Medical Services (EMS).

“It took about 20 minutes for EMS to arrive,” Habermehl testified.

Officer Kyle Thomas Daly found Shemel, bleeding heavily, seated on a toy car and leaning against the wall, said the New York Daily News.

“I put on gloves, took her off the car and laid her down and began rendering aid,” said Daly, who has since left the NYPD to join the Suffolk County police department in Shirley, Long Island, a New York City suburb. “She regained consciousness, gave me her name and date of birth. “It took a very long time for the ambulance to come, about 20 minutes.”

While Shemel was in and out of consciousness, the dying teen told another detective that Stephens wanted to be “boyfriend and girlfriend”, but she wasn’t interested, Daly said.

Shemel and Stephens reportedly met at a day care centre a week before the murder and exchanged phone numbers.

An ambulance arrived at 6:55 pm but Mercurius died at Kings County Hospital at 7:57 pm, according to testimony.

Shemel, who lived with her aunt after moving to the US four years ago from Guyana, had buzzed a friend into the East Flatbush building where she was babysitting moments before she was shot.

It said Lona Junien took the stand to describe what she saw happening between Stephens and Shemel when she showed up to visit her friend.

“The person pushed her. The person said ‘Don’t ever lie to me.’ She was screaming, he took out the gun and shot her,” said Junien, 18.

Junien admitted on cross-examination that a detective told her Stephens was the shooter before she identified him.

If convicted, Stephens faces 25 years to life in prison for second-degree murder and weapons charges.