The Rocklin Police Department says it has arrested an 18-year old man and two minors linked to threats against two high schools made via social media.
Police say they discovered the threats, which involved school gun violence, on twitter, against Whitney High School and Rocklin High School.
Investigators then tracked down the identities of three suspects believed to be involved in the threats, and arrested them.
Police say parents and students were already on edge after other, apparently unrelated threats made through Instagram.
Rocklin police say they have also increased patrols around the school Friday.