The graffiti was blatant and violent in language.
"(Expletive) Christ and your evil empire," reads one.
"We've come to dismantle the Mormon empire," read another. One promised that the "Knights of Satan" would claim Mormon children.
The FBI now considers the graffiti spray-painted outside The Church of Jesus Christ of Latter-day Saints' seminary building at Highland High School a hate crime. The graffiti was discovered at the Salt Lake school on Jan. 11. Spray-painted arrows led from message to message to message.
"This is more than just kids playing. This is something extending beyond that," FBI Special Agent Juan Becerra said Wednesday. "It's trying to send a message where a church is not welcome."
Becerra said the FBI and Salt Lake City police are pursuing a few leads, but they need the public's help.
"If it is kids being stupid, I would ask them to turn themselves in," he said. "We consider it a hate crime."
The LDS Church is cooperating in the investigation.
"Given that this is an open and ongoing investigation, it would be inappropriate for us to comment," said church spokesman Scott Trotter.The FBI said a reward is being offered for information. Anyone with tips is urged to call Salt Lake City police at 801-799-3000 or the FBI at 801-579-1400.