Miami police officers Jonathan Aledda and Commander Emile Hollant have both been placed on administrative leave without pay after giving conflicting statements to investigators. North Miami City Manager Larry Spring Jr added that Aledda was a four-year police department veteran.

Mayor Smith Joseph has apologised to Charles Kinsey, an African-American carer who was trying to help his patient who has autism back to a mental health care facility.

"I have made it clear that I will not tolerate anything that goes against the process," the mayor said, adding that a complete investigation of the shooting would be carried out.

The police officer said he had been aiming at the white, autistic patient beside Kinsey, but missed, hitting the behavioural therapist in the leg by accident. Kinsey was then handcuffed and was on the ground for 20 minutes before an ambulance arrived.

The 54-year-old was taken to hospital with a gunshot wound to his right leg after two or three shots were fired, according to his lawyer.

Clint Bower, who runs the care home where Kinsey has worked for over a year, queried the explanation given by police officials.

"The (union) is now trying to say they intended to shoot my client and instead they shot my employee," he told CNN. "To me, that's just outrageous."

"Mr Kinsey is a hero today. He saved the life of that disabled individual," said Bower.

"This individual he was caring for is a person with significant behavioural issues, and Charles was specifically chosen to work with this individual as his one-on-one staff, because he is that much of a skilled employee," Bower said. "He has received extensive crisis intervention training. Unfortunately, our police department doesn't seem to have received that same training."

Kinsey told WSVN that he asked Officer Aledda: "I'm like, 'Sir, why did you shoot me?' "He said to me, 'I don't know.' "

The therapist expressed surprised and dismay that he was shot. "As long as I've got my hands up, they're not gonna shoot me, that's what I'm thinking," he said. "Wow, was I wrong."

"As long as I've got my hands up, they're not gonna shoot me, that's what I'm thinking," he said. "Wow, was I wrong."