A Baltimore State's Attorney animated video detailing events of the arrest and death of Tyrone West on July 18, 2013. No police officers involved will be criminally charged after the medical office could not determine the manner of West's death.

Baltimore police were legally justified in using their fists, batons and pepper spray to subdue Tyrone West before he died while resisting arrest this summer, State's Attorney Gregg L. Bernstein said Thursday.

The officers involved in the case used "objectively reasonable force" and will not face charges, Bernstein said. The announcement concludes the criminal investigation in a case that began with a traffic stop and became the focus of increasing public pressure amid angry protests by West's family.

The office of the chief medical examiner found that West died from a heart issue made worse by dehydration, the July heat and his struggle with police. Though the autopsy report details the officers' use of force, it says he did not suffer any injuries that could have killed him.

The state medical examiner could not conclude whether the death resulted from an accident, homicide or other means.

"Mr. West's death was caused by a number of factors while actively resisting arrest … necessitating the use of objectively reasonable force by the officers to subdue and contain a suspect," Bernstein said.

Prosecutors met with West's family Thursday morning, but later wouldn't let his relatives attend a news conference. Standing on East Baltimore Street outside the state's attorney's offices, West's family members said they did not believe Bernstein's conclusions.

"I don't care if it kills me, we're going to get justice," said Diane Butler, West's aunt. The family said they were especially upset with the release of the report just days before Christmas.

The autopsy report and the description by prosecutors provided the most detailed account to date of how a traffic stop deteriorated into violence over the course of 15 minutes.

Bernstein said two officers stopped West's car, and, while he initially complied with their orders, he soon began to resist. A woman in the car with West shouted at him to calm down, Bernstein said, but he ignored her pleas.

The officers — incapacitated by their own pepper spray — called for backup. Police eventually pinned West down, and he died as they held him on the ground, Bernstein said.

Michael E. Davey, an attorney at Schlachman, Belsky & Weiner who represented all nine of the officers in the investigation, welcomed the prosecutors' findings.

"We are very happy with decision from the state's attorney's office," Davey said. "It was the absolute right decision. No police officers did anything wrong."

Bernstein had faced increased pressure to release details about his investigation, as Mayor Stephanie Rawlings-Blake urged him to share information with West's family. The City Council, meanwhile, recently held a hearing on delays in the medical examiner's release of the autopsy.

In a statement Thursday, Rawlings-Blake said she had "closely monitored" the case and would ensure that the police conducted a thorough internal review.

"We have to continue to strike the right balance between making sure communities don't feel under siege and our police officers are able to do their jobs in ridding our streets of the most violent offenders," the mayor said.

The eight Baltimore Police Department officers involved will now face an administrative review and remain assigned to desk duties, spokesman Lt. J. Eric Kowalczyk said. Police also plan to have an independent commission carry out a third review as they did with the death of Anthony Anderson, who died in police custody late last year.

In a statement, the department said police "must have and will continue to have a reverence for human life."

"There will never be a perfect solution to every encounter," the statement read. "We will never stop in our efforts to reform and better our methods."

Morgan State University said a campus officer who also responded is on active duty.

Police and prosecutors interviewed numerous police and civilian witnesses as part of their investigation, including a woman who was riding in a car with West.