KANSAS CITY, Mo. – For four years, she was known only as Precious Doe, a little girl whose headless body was found along a road. Yesterday, police identified the girl, arrested her mother on murder charges, and pronounced the sad mystery solved.

The girl with big brown eyes and neat cornrows in her hair was identified as Erica Michelle Marie Green, just shy of 4 when she was found.

Her mother, Michelle M. Johnson, 30, and stepfather, Harrell Johnson, 25, were charged with murder and endangering the welfare of a child.

Police said Harrell Johnson admitted that under the influence of alcohol and the hallucinogenic drug PCP, he became angry with Erica when she refused to go to bed, grabbed her, kicked her, and threw her to the ground, leaving her unconscious. After she died, he said he used hedge clippers to sever her head.

Both suspects were being held in Oklahoma, where they live.

“We have closure,” Police Chief James Corwin said. “The little girl that we’ve known for four years as Precious Doe has a name.”

Police said a tip enabled them to identify Erica, but they would not elaborate. Her body was found near an intersection on April 28, 2001. Days later, her head was found nearby, wrapped in a trash bag.

In the months after she became known as Precious Doe, hundreds attended candlelight vigils, volunteered to answer witness hot lines, and passed out fliers with an artist’s rendering of the girl. The FBI took blood samples from family members of missing black girls, and the case was featured on television’s “America’s Most Wanted.”

A makeshift memorial of poems, teddy bears, and flowers was eventually replaced by a permanent memorial in a park near where her body was found. Yesterday, among flowers and balloons, a handwritten sign announced: “My Name Is Erica Michelle Marie Green.”

Authorities said the little girl was killed in Kansas City, where the family had been staying with a friend. According to court papers, Ms. Johnson said her husband kicked Erica in the head, and they left her on the floor for two days. They did not seek medical help, she said, because both had warrants out for their arrest.

The child died, and the couple carried the body to a church parking lot, then through the woods, where the stepfather cut the girl’s head with hedge clippers, police said.

The break in the case apparently came after community activist Alonzo Washington, who has long championed efforts to find out who the little girl was, placed another advertisement seeking leads in a local paper.

“There’s something about it that just bothers me that a child could be thrown away and people forget about it,” said Mr. Washington, who has worked to raise awareness of missing black children.

Michelle Johnson was being held on $500,000 bail in her hometown of Muskogee, Okla., and will be brought to Kansas City as soon as possible, prosecutor Michael Sanders said.

The prosecutor asked that her husband be held without bail and that the couple be extradited to Kansas City as soon as possible.