The text message led to the lockdowns of all Middletown schools, Lakota East High School and the Lakota East Freshman campus. Those lockdowns lasted more than three hours until about 12:30 p.m. on Wednesday.
The message was received by the wellness center on the Middletown High School campus, which sends messages confirming appointments. The text message received was a response to that appointment reminder, officials said.
The student was identified, found with the phone that sent the text message and confessed, police and school officials said.
Officials said a phone with a number related to the phone that sent the message was “pinged” at Lakota East High School, which caused the lockdowns there.