A 6-year-old Missouri boy's mother, grandmother and aunt face charges after authorities said they staged his kidnapping because they believed he was too nice to people and they wanted to teach him about possible danger from strangers.

The Lincoln County Sheriff's Office said Thursday the three wanted to scare the boy. Authorities say they enlisted help from the aunt's co-worker, who lured the child into his pickup after he got off a school bus Monday.

Authorities said the man told the boy he wouldn't "see his mommy again," and that he'd be "nailed to the wall of a shed," the St. Louis Post-Dispatch reported. He showed the boy a handgun in an effort to make him stop crying, authorities said.

The man tied the child's hands and feet with plastic bags and blindfolded him with a jacket, the sheriff's office said, before he drove the boy to his Troy home. Authorities said the boy was kept in the basement for a while, before untied and told to go upstairs, where he was lectured about staying away from strangers.

Investigators said the boy's family said they wanted to educate him about the harm of talking to strangers and felt they didn't do anything wrong.

The mother is charged with felony kidnapping and abuse or neglect of a child. The others are charged with felony kidnapping, felonious restraint, and abuse or neglect of a child. All four were being held in Lincoln County Jail in lieu of $250,000 bail. It wasn't immediately known if they had attorneys.

Police were alerted after the boy told school officials. He has been placed into protective custody.