Police interviewed the teacher at Fulton Academy in the suburb of Aurora after a student told her mother who then reported Thursday's incident to police. The student confirmed to police the teacher's statement to an officer that it was a joke, the children were laughing, and had asked that their mouths be taped.
In her statement to police, the teacher said she didn't "think anything bad" about placing tape a small, vertical strip of transparent tape on all 28 students' mouths.
"The incident did not meet the elements of any municipal violation or state statute," Aurora police said in a statement.
The unidentified teacher is on paid administrative leave while the Aurora Public Schools district investigates.
"My daughter's been in the house crying, begging me not to send her back to school. (She) said that she'll do good in home school and she promises. She doesn't want to go back to a public school," Tenisha Bynes told KUSA-TV.
The girl said the punishment was painful.
"When she put it on, it was like, OK, and then, like, it started to hurt my mouth right here. It's also hard for me to breathe with the tape, too," she said. The girl's name is being withheld because of her age.
The teacher did not return a phone call to the station seeking comment. The teacher's name was redacted in a police report because no charges have been recommended.
The school is under the jurisdiction of Aurora Public Schools with limited responsibility for making its own decisions.
The school district issued a statement saying it's taking the matter seriously and will conduct its own investigation.
"Due to privacy laws, we are unable to discuss these allegations specifically. When we receive allegations of this nature, we immediately contact the police, begin our own investigation and possibly place the staff member on administrative leave during the investigation. We do not condone any inappropriate adult conduct toward students, and we cooperate fully with the police," said spokeswoman Paula Hans in an email statement.
Information from: KUSA-TV