An 18-year-old female Centennial High School student was in custody Thursday after allegedly threatening a mass shooting at the school on social media.

Toni Strickland (Clark County School District via Las Vegas Metropolitan Police Department)

An 18-year-old female Centennial High School student was in custody Thursday after allegedly threatening a mass shooting at the school on social media.

Toni Strickland is facing charges of making a terroristic threat and making a bomb threat, school police Capt. Ken Young said Thursday.

A screenshot of a text message conversation that circulated among students on social media included the message “We shooting up your school tomorrow no one safe” after asking the recipient whether they attended Centennial High School.

Police saw multiple images and screenshots from different social media platforms, all with similar information. After talking to parents and students who saw some of the images, investigators were able to trace it to Strickland, Young said.

Police do not believe Strickland intended to carry out the threat, saying there was no credible evidence.

“At this point, there is no clear motive, other than bad judgment,” he said.

Strickland was arrested and taken into custody from her residence around 11:30 p.m. Wednesday, Young said. Earlier, more than 300 calls were fielded by Metropolitan Police Department and school police.

The school district said Wednesday it appeared similar threats were made across five states this week, and the school district was working with local law enforcement in the broader investigation.

Contact Meghin Delaney at mdelaney@reviewjournal.com or 702-383-281. Follow @MeghinDelaney on Twitter.

Some of you have reached out about an unsubstantiated threat that has been circulating online about a possible school shooting this week — CCSD (@ClarkCountySch) October 5, 2017

We are working with local law enforcement partners to investigate this threat. It appears similar threats have been made in 5 other states — CCSD (@ClarkCountySch) October 5, 2017

At face value, we don’t believe the threat to be credible. We are working with local law enforcement to expedite the investigation. — CCSD (@ClarkCountySch) October 5, 2017