MIAMI, United States (AFP) – A US policeman who shot and wounded an unarmed black therapist who was trying to help an autism patient has been arrested and charged with attempted manslaughter, officials said Wednesday.

The shooting happened last July in Miami outside a group home where the man with autism lived and behavioural therapist Charles Kinsey worked. It triggered protests in Miami among the Black Lives Matter movement.

The officer who shot Kinsey, Jonathon Aledda, surrendered on Wednesday in response to a warrant for his arrest on charges of attempted manslaughter and culpable negligence, the Miami-Dade County State Attorney’s Office said.

At the time, police said they were responding to an emergency call about a man with a gun walking around and threatening suicide.

Kinsey was shot in the leg as he lay on the ground with his arms raised and pleaded with officers to hold fire. He had been trying to help an autistic man who had wandered away from the group home.

The incident was captured on cellphone footage that went viral. It included shots of the heavy-set young autistic man, Arnoldo Soto, sitting on the ground playing with a small white toy.

In the video, Kinsey can be heard shouting to police: “All he has is a toy truck. A toy truck. I am a behavioural therapist at a group home.”

“Once Mr Kinsey saw two officers park and arm themselves with assault rifles, he placed his empty hands in the air and began to plead with Mr Soto to cooperate. Mr Soto was not responsive to Mr Kinsey’s pleas,” Special Agent Daniel Mosquera, who led the investigation into the shooting, said in an affidavit.

“No other officer on the scene observed Mr Soto exhibit any behaviour that compelled them to shoot,” Mosquera added.

After the shooting, Kinsey told a local TV station he had pleaded with police not to shoot him.

Kinsey added: “It was like a mosquito bite, and when it hit me, I’m like, ‘I still got my hands in the air, and I said, ’No I just got shot! And I’m saying, ‘Sir, why did you shoot me?’ and his words to me, he said, ‘I don’t know’.”