A 23-year-old California man has been arrested after police were tipped off to comments he made on an online gaming platform allegedly threatening to commit a mass shooting at a synagogue. The Concord Police Department identified the man as Ross Farca in a statement outlining the charges on Saturday. Farca wound up on the FBI’s radar after making numerous threats online, including threats against Jews, law enforcement, and claims of owning an AR-15, police said. A subsequent search of Farca’s home is said to have uncovered an illegal AR-15 that had been built from a legally purchased frame, as well as Nazi literature, camouflage clothes, and a sword. Farca has been charged with making criminal threats, possession of an illegal assault rifle, and manufacturing an assault rifle, though police say he never mentioned any specific locations in his threats to carry out an attack.