NORTHRIDGE, CA — As finals begin at Cal State Northridge, students and staff are, once again, facing the threat of a mass shooting. An expletive-filled letter appeared on social media this week threatening to kill everyone on campus Dec. 12 and that a mass shooting would also be carried out the same day at the adjacent Northridge Academy High School.

Last week, authorities investigated a similar threat that was scrawled onto a bathroom wall at the university. Authorities have not determined whether the threats are credible. As a precaution, school officials have beefed up campus security throughout finals week. "I am writing this to inform the people of CSUN that I will kill everyone on the 12 of December 2018," the letter said. "I am aware that I will probably (be) shot and killed, but before that happens, I'm killing as many (expletive) as I possibly can."

The suspect said a tandem shooter would target bully's at Northridge Academy High School. "He's gonna give bullys (sic) what they deserve, death," the letter said.

Police won't be able to protect the students and staff, the letter writer threatened. "The teachers and proffesors (sic) are surely going to (expletive) die for making students depressed and giving us (expletive) work that will never serve us good in life. You (expletive) are gonna bleed to death."

As of Monday morning, police and school officials had not yet determined if the threat is credible, said CSUN Police Chief Anne Glavin. There is no imminent threat to the school, she stressed. The Los Angeles Police Department is assisting in the investigation, she added.

In response to recent threats of violence and the discovery of racist graffiti on campus, the school's president announced Wednesday there would be an increased police presence at the school throughout finals week.

"Sadly, the world in which we live requires we take threats of violence and expressions of hate seriously -- even when there is no evidence to suggest that the threatened acts are likely to materialize," CSUN President Dr. Dianne F. Harrison said. Harrison said she understood there may be some objection to an increase in law enforcement on campus, but said the move is warranted.