LEMON GROVE (KGTV) - Mount Vernon Elementary School parents Tuesday were alerted to heightened security a day after the school received an anonymous threat.
Parents received a letter that a "threat of violence" was emailed to Principal Russell Little Monday, though the origin of the letter could not be established.
"While threats of this nature are sometimes made by school students, we still have not determined the identity of the sender," Ernie Anastos, superintendent of the Lemon Grove School District, wrote. "For this reason, we will have an increased Sheriff Department presence on our campus today."
Anastos asked parents to speak with their children about the threat and how to stay vigilant and safe on campus.
"We will continue to be vigilant about campus security, and invite you to assist," Anastos wrote. "Let your student know that if he or she notices any suspicious or threatening behavior, he/she should report it to Mr. Little or any other employee of Mount Vernon Elementary School."
The school district is currently working with the sheriff's department to weigh the credibility and origin of the threat.
