Crying boy's hug with police officer becomes one of the most shared images of Ferguson protests

Devonte Hart had been holding a 'free hugs' banner at the protest

Portland police Sgt. Bret Barnum, left, and Devonte Hart, 12, hug at a rally in Portland, Ore., where people had gathered in support of the protests in Ferguson (AP)

A picture of a tearful young demonstrator hugging a police officer has become one of the most enduring images from the Ferguson protests, after it was shared across Facebook more than 400,000 times.

Twelve-year-old Devonte Hart was holding a sign offering “free hugs” during a protest on Tuesday in Portland, Oregon against a grand jury’s decision not to charge white officer Darren Wilson for killing unarmed black teen Michael Brown.

The image, shot by freelance photographer Johnny Nguyen and published by The Oregonian, showed a man identified as Portland Police Sgt. Bret Barnum hugging Devonte as tears streamed down his face.

Devonte is one of six children adopted by Hart and her wife, Sarah Hart of West Linn, a suburb of Portland.

Officer Barnum, who works for the traffic division, had been dispatched to help with traffic and crowd control.

The Associated Press reports that Barnum had also "liked" a Facebook post by an officer of a badge of the Portland Police Bureau with an "I am Darren Wilson" banner earlier that week. The officers were later ordered to remove the images and the matter is under an internal investigation.

In a Facebook post explaining the picture, the boy’s mother Jennifer Hart wrote on social media that her son had been struggling with issues of police brutality and racism.

"Devonte struggles with living fearlessly when it comes to the police and people that don't understand the complexity of racism that is prevalent in our society,” she wrote, according to The Oregonian.

“He trembled holding a Free Hugs sign as he bravely stood alone in front of the police barricade.”

She said Officer Barnum approached Devonte, extended his hand and asked him questions about school and his plans for summer.

“Their interaction was uncomfortable at first. There were generic questions […] but the one that mattered hit straight to the heart. He asked Devonte why he was crying.

“His response about his concerns regarding the level of police brutality towards young black kids was met with an unexpected and seemingly authentic (to Devonte), ‘Yes. *sigh* I know. I'm sorry. I'm sorry.’ The officer then asked if he could have one of his hugs.”

Barnum told AP he had spotted Devonte's "Free Hugs" sign on the ground and asked if he might get a hug as well. He said Devonte then embraced him.

"Knowing how he struggled with police, his bravery and courage to catch my eye and approach me were impressive," he said. "And it's a blessing for me that I didn't miss an opportunity to impact this child."