This story was updated Feb. 20, 2018, at 11:49 p.m. with more information.

Three students are in custody after making what were perceived as threats to student safety at area high schools. It's the latest in a string of local hoax incidents following last week's deadly Florida school shooting.

A Ringgold, Ga., high school student is accused of making a new Snapchat account, sending herself a threatening message and passing it along to other students, making it look like she was the target of a dangerous plot.

The Catoosa County Sheriff's Office charged 17-year-old Alexandria Justine Greene, of Cemetery Road in Ringgold, with falsely reporting a crime Monday night. According to an incident report, other students heard about the threatening message and alerted the police.

Greene told investigators that someone named Kevin Garrett added her on Snapchat on Monday evening, under the username KEVGARR234. She said she didn't know him and thought he was trying to reach someone else. Greene, who is black, showed an investigator a message threatening to kill her and using multiple racial slurs.

She said Garrett also called her.

"She was unable to make out what the person was saying," the officer wrote, "but it sounded like a man's voice and was very deep, but not saying words."

Greene took a screenshot of the message she received on Snapchat and passed it along to others. She did not tell her mother about the threat for two hours, according to the report. One student alerted the police about what happened. Another student told a teacher.

Officers checked a database and could not find a Kevin Garrett at Ringgold High School. One message referenced the Youth Detention Center, so an officer checked a database there, too. There was no Kevin Garrett, according to the report.

An officer checked the IP address for Kevin Garrett's Snapchat account. According to the report, the message came from Greene's own house.

Greene then admitted to making the account and sending herself the message, according to the report. She is the legal age to be treated as an adult in Georgia.

In a separate incident, a Chattanooga girl was charged with filing a false report after a meme parents perceived as a threat was circulated on social media Monday afternoon.

The Hamilton County Sheriff's Office, Chattanooga Police and East Ridge Police were made aware of the meme around 4 p.m. and began investigating, according to a news release. The message contained what many students and parents thought might be a threat or warning pertaining to three schools in Hamilton County.

Authorities managed to track it to a juvenile who was identified as the creator of the meme. It was determined there was no real threat, but charges will be filed in juvenile court against the girl because her actions caused significant community alarm.

A joint release from all three law enforcement agencies stated that any and all "threats or perceived threats against our community's schools and our community's children will be investigated."

It adds that anyone who participates in creating hoaxes or threats will be prosecuted and any electronic devices used in such an act are subject to search and seizure.

The arrests come days after three Bradley County students were arrested for allegedly threatening to shoot up Bradley Central High School; another student was jailed after a social media threat against Meigs County High School. A spokesman for Rutherford County Schools also said false rumors had been spread to parents and students, but no credible threats were made.

In a statement emailed Tuesday evening, Hamilton County Schools spokesman Tim Hensley reminded students to think about the consequences of what they say and do online.

"Young people do not always think through consequences, and teens find themselves in serious trouble perpetuating hoaxes on social media or making comments perceived by others as threats," the statement reads. "Our high school and middle school principals have sent a message to parents asking them to please discuss with children the importance of carefully choosing the language they use and images they post on social media accounts. Communication that may be viewed as a threat can result in very serious problems for the child and family at school and in the legal system."