Lincoln Township Police were called to Upton Middle School late Monday morning after a message was written on a bathroom wall.

Video surveillance led police to center in on a 13-year-old who admitted writing the message.

A second threat was then found, and the alleged author of that threat was also taken on to custody.

On Monday afternoon, police were called to Lakeshore High School regarding the discovery of a threat.

In this instance, it was a handwritten message. No particular student was mentioned.

Police are reviewing surveillance video to try to help find the author. As a result of the threat all Lakeshore Public Schools are closed on Tuesday.