New video showing a mentally ill Florida man being shot dead by police calls into question a Miami area department's explanation of the shooting, said attorneys for the victim's family who released the footage on 8 April.

Footage captured from within a police car at the scene show shell cases flying as a police officer shot 25-year-old Lavall Hall on 15 February.

Before the shooting, an officer can be heard shouting: "Get on the f***ing ground or you're dead." Five shots followed.

Two of the bullets hit Hall, Miami Gardens police told reporters in the days after the incident, explaining that Hall had attacked officers with a broom stick.

The video does not show Hall at the moment of the shooting. Beforehand, he can be seen walking and at times running around a Miami suburb, holding a broom handle.

His attorney told reporters that he had been running away from police at one point, although he appears to chase them at another.

"The officers had made up their minds, that they were going to kill Lavall before this incident took place," Attorney Glenn Goldberg told a news conference on 8 April.

A spokesman for the Miami Gardens Police Department was not immediately available to comment.

An attorney for Eddo Trimino, the officer involved, told the Miami Herald the video indicated that he had shot out of fear

The video was released amid national protests over a series of deaths resulting from police use of force, most recently with another video showing a white South Carolina police officer shooting an apparently unarmed black man in the back.