Lake Zurich High School student taken into police custody after threat leads to lockdown

Lake Zurich High School went into a hard lockdown Wednesday afternoon after a student posted on social media threats of imminent violence, authorities said.

The lockdown, also imposed at nearby May Whitney Elementary School, was lifted after police found no indication of danger and took the student who made the threat into custody.

The threat came shortly after 1:25 p.m., when officials lifted a soft lockdown imposed earlier in the day when a bullet shell casing was reportedly found on campus, according to Lake Zurich Unit School District 95. No threat was reported at that time, nor was any weapon found, police said.

The hard lockdown ended about 2:40 p.m., after police swept inside and outside the school, and students were dismissed as scheduled later in the afternoon.

"The prompt response in calling these lockdowns at the high school was made possible by students who acted appropriately by promptly reporting information to a high school staff member, and by staff members following emergency protocols," Lake Zurich police said in a statement Wednesday.

Though policies differ among school districts, typically hard lockdown means students and teachers shelter in place in classrooms and every door in the building is locked. During a soft lockdown, exterior doors typically are locked, but students are allowed to move freely within the building.

"Please know that many students and staff are understandably upset by today's incidents," school officials said in a statement on the district's website. "We will be developing a plan to provide support. More information will be provided soon."