A student was arrested for the Class C offense of causing a disturbance on a school bus. His cellphone was taken from him during booking and placed in the jail property room.

Later that day, the police officer assigned to the campus was told that the student had used his cellphone to take a photograph of another student urinating in the school bathroom. The school police officer drove to the jail, retrieved the cellphone from the jail property room, turned it on and went through it until he found the photograph. He then took the phone back to his office, printed a copy of the photo and kept the phone as evidence.
 
The student was charged with the felony of improper photography, and argued that the school police officer could not search his cellphone without a warrant.

The trial court ruled that the photo had been illegally obtained and could not be admitted. On appeal, the court of appeals affirmed, ruling that a citizen has a reasonable expectation of privacy for the contents of his cellphone for purposes of the Fourth Amendment, which governs the circumstances under which the police can search a person or property as part of a criminal proceeding.

The court did note that a person can lose that expectation under some circumstances, such as if the cellphone is abandoned, given to someone else to use, or if consent to a search is given. However, the court concluded that a citizen does not lose the expectation of privacy for the contents of his cellphone merely because he has been arrested and his phone is in police custody for safekeeping. A warrant was required before the police could search the contents of the phone.

Although this was a criminal case and the people searching the cellphone were police officers, teachers should be mindful of potential limitations on the ability to search the contents of students' cellphones.