When Jameek Lowery started filming inside a New Jersey police station, he was panicked and afraid. As he waited for an ambulance, he told officers he was paranoid and insisted they were trying to kill him.

Two videos he streamed live to Facebook depict a frantic Lowery, 27, asking viewers for help and calling out to the Paterson, New Jersey, police officers for water. Then he turned the camera towards himself.

“Ma, I’m sorry,” he said. “They’re going to do this to me. They’re going to kill your baby boy.”

About 10 minutes later, Mr Lowery, a father of three, was unresponsive. Two days after that, he was pronounced dead at a nearby hospital.

The Passaic County prosecutor is now investigating Mr Lowery’s death, as protesters continue to press for an explanation of what happened during the time he was in transit from the police station to the hospital.

“We plan on continuing and increasing our actions until we get justice,” said Zellie Thomas, 34, a teacher and community organiser from Paterson.

While officials held a public meeting about Mr Lowery’s death inside Paterson’s City Hall earlier this week, a rally outside turned chaotic, with participants reporting on social media that police used pepper spray on protesters.

Mr Lowery first called 911 in the early hours of Saturday morning. He told dispatchers he had taken ecstasy and was paranoid, according to the Passaic County prosecutor’s office. An ambulance took him to a nearby hospital, but he left “sometime after becoming erratic,” the prosecutor’s office said.

Then, around 3.45am, Mr Lowery called 911 again and said people were trying to kill him. After making that call, he walked into Paterson’s police headquarters asking for assistance. Officers called for an ambulance.

While he was waiting, he began recording. In the footage on Facebook, officers kept their distance as Lowery repeated that he believed they were trying to kill him. As he filmed, Mr Lowery told the officers he would not harm them.

“I’m good,” he said. “I’m just paranoid.”

“You’ve got to breathe,” one of them responded.

A protester tries to block the camera as they face Paterson police officers during a rally on 8 January 2019 (AP)

Throughout the videos, which lasted more than five minutes, officers responded by telling Lowery they did not want to kill him.

Mr Lowery is heard repeatedly asking for water, but is told officers are “not allowed” to give him anything; one officer said he would get water in the ambulance or at the hospital.

He appeared to be sweating profusely, with chapped lips. “All right,” he said to the officers just before the footage ends, “go ahead and kill me.”

Paterson’s mayor, Andre Sayegh, said in a statement that Lowery walked to the ambulance on his own. The prosecutor’s office said Lowery had to be restrained during the mile-long trip and officers used “physical force and compliance holds to secure him.”

Officials said they are awaiting toxicology and autopsy reports from the medical examiner’s office, and a cause of death had not been determined.

On Tuesday, hundreds of protesters gathered for a march outside City Hall to call attention to Mr Lowery’s death, according to Mr Thomas.

But protesters instead headed towards the police station, Mr Thomas said, and at least one officer used pepper spray on the crowd.

Paterson’s police director, Jerry Speziale, and its police chief, Troy Oswald, did not immediately respond to requests for comment. A spokesperson for Mr Sayegh’s office declined to comment.