A months-long drug investigation at a north suburban Lincolnshire school is expected to wrap up Tuesday, but some parents aren't happy with the way their kids were treated by school administration and police.



The public information officer at Adlai E. Stevenson High School said last week administrators and law enforcement received "credible evidence" of drug activity on campus in late-December. They subsequently confiscated student cell phones to carry out the investigation and identify suspects.



School board president Bruce Lubin on Monday revealed more details at a public meeting about the drug investigation and defended the way it was carried out.



He said the drug probe occurred in December and January, that students' cell phones were seized and text messages read, and two students were arrested on drug charges.



"Please understand that we are legally and ethically limited in the type of information that we share within and outside the school about matters related to students and student discipline," Lubin said in a prepared statement on behalf of the school board. "And as it relates to the issue of impairing or intoxicating substances, we take this matter very seriously."



Administrators said their actions were legal, but parents are still concerned.



"We're really getting no facts, so that is a concern obviously," parent Jack Peiser told NBCChicago.



There's no word on how many students were expelled or suspended in the investigation.

