A mother in the United States faces up to six months in prison for allowing her four-year-old son play alone in a playground 120 feet from her front door, Yahoo reports.

The mother, a self-described “free-range” parent, lives with her son in a gated community in Sacramento. Two neighbours – a mother and daughter - watched the boy, Tomahawk Hendren, playing alone in the playground and then approached him and told him to go home. The boy then told the neighbours he wasn’t finished playing, so they called the police.

From there Child Protective Services became involved and the mother now has to wait to see if the prosecution can prove she wilfully put her son in danger. If that is possible they will move forward with child endangerment charges.

While the initial arrest was on felony charges of child endangerment and neglect, Ms Hendren’s charges have now been reduced to misdemeanours. This means she now faces the choice of taking a 30-day stint in prison, and one year probation, or possibly facing a six-month sentence if found guilty.

“I just thought she would get a warning,” said Brandi Horrell, one of the neighbours who reported Ms Hendren.

“I’m not mad she has to do things now to teach her, because what if someone did take him?”

"How would she feel if he was on an AMBER Alert? Then what would she be feeling?" Sonja Horrell, Brandi’s mother – who also called the police - said, referring to an alert system for missing children.

Alin Cintean, Hendren’s attorney, said: "If this had happened 20 years ago, we wouldn't be here. There wouldn't be a criminal case filed," Cintean said.