The man was arrested with a concealed knife in his possession. A Cotati man who threatened online to bring a knife to his son’s school — prompting an evacuation Monday — was arrested hours later with a concealed blade in his possession, authorities said.

Two schools in Sonoma County were placed on lockdown Monday following what authorities called a “credible” threat. Approximately 220 students at Harmony Elementary and Salmon Creek Middle School, which share a campus in Occidental,

The Sonoma County Office of Education (SCOE) said a threat posted on social media by a student’s father caused two schools to go into lockdown Monday morning. SCOE said the online threat is being handled by the Sheriff’s Office in an ongoing criminal investigation.