Two teenagers were arrested Monday in connection with the death of a 5-year-old girl who vanished from her great-grandmother's house and whose body was found dumped in a garbage can, authorities said.

The arrests came after one of the teens went to police Monday morning and led them to a garbage can containing a trash bag holding the body of Isabella Tenant, authorities said. He told them he had helped a friend dispose of it after the friend had killed her, they said.

Isabella's family had called police earlier Monday to say she was missing from her great-grandmother's home in Niagara Falls, where she'd been staying overnight. Isabella's great-grandmother said she had last seen her Sunday night with 16-year-old neighbor and family friend John Freeman.

Authorities said it was Freeman's friend, 18-year-old Tyler Best, who led them to her body, which he said he helped Freeman hide. Authorities said it appeared Isabella had been killed without weapons being involved.

Police on Monday said they had charged Freeman as an adult and he faced a murder charge. They said Best was charged with tampering with evidence.

Freeman and Best were in custody and couldn't be reached for comment Monday. There was no listed home phone number for them, and no information about attorneys was available.

Freeman and Best were scheduled to be arraigned Tuesday.

At a news conference Monday afternoon, police Chief Detective William Thompson said there were signs of injuries but no indication of sexual abuse.

"It's a terrible crime," he said. "It tears at your heart."

Of Best going to police, Thompson said, "I imagine it was his conscience."

An autopsy was planned for Tuesday.