A second case of a Spanish Fort High School student posting a threatening image on social media led to a swift arrest Thursday and a schoolwide assembly intended to make it clear that such actions will not be tolerated.

“The assembly was put together after her arrest because of the two incidents we’ve had in one week and with spring break,” said Police Chief David Edgar. The 15-year-old girl was taken to the county juvenile detention center and charged with making terroristic threats.

Baldwin County District Attorney Robert Wilters and Edgar did most of the talking to the students, Edgar said. “It wasn’t a dialogue. It was a monologue between myself and Mr. Wilters and the kids.”

Also on hand were school and school system administrators, Mayor Mike McMillan and a juvenile probation officer.

Edgar said the case was similar to the one Sunday that led to the arrest of two Spanish Fort students. The girl posted a photo of herself holding a BB gun. The image and the threatening language were similar to what was posted on Sunday, he said.

On Thursday morning, someone shared the image with the police department’s school resource officer at Spanish Fort High. The officer recognized the girl and immediately involved others with the department, Edgar said.

In an email message sent to parents and others associated with the high school and Spanish Fort Middle School, Edgar said in part, “We have a zero tolerance policy. Whether it is intended as a prank or a joke, it is taken seriously by law enforcement and the court system — do not do this.”

The Mobile Police Department, meanwhile, has arrested nine juveniles and one adult for making bomb threats in the last 11 days. Edgar said those incidents do not appear to be related to those in Spanish Fort, but both departments are comparing notes. Nor was Thursday’s incident connected to the arrests of four middle school students in Foley who were allegedly threatening to bring guns to school.

Since spring break starts next week in Baldwin County, Edgar said authorities also took advantage of the assembly to emphasize that alcohol and drug abuse will not be tolerated either, at large parties or at the beach.