Detroit — Wayne County Prosecutor Kym Worthy said Thursday she’s charged 23 youths with school threats and is investigating 10 more cases.

Worthy and Detroit Police Chief James White held a press conference at Detroit Public Safety Headquarters to discuss a recent rash of school threats, including a social media threat that resulted in the closure of Henry Ford High School in Detroit.  

Since the Nov. 30 Oxford High School shooting that left four students dead and seven other people injured, Worthy said her office has investigated “copycat cases” throughout the county. Ten of the announced charges involve Detroit students, with the other 13 spread countywide.

Similar charges have been brought against students throughout southeast Michigan. Oakland County school and law enforcement officials last week said they were experiencing a “tidal wave” of school closures in response to threats. In southeast Michigan, more than 60 school districts canceled classes because of threats.