Police ID 12-year-old as sender of threatening tweet against against Alum Rock Union School District

SAN JOSE, Calif. (KGO) -- Relief this morning for parents and students at the 27 campuses in the Alum Rock Union Elementary School District.

Police say they have identified the person who sent out a threatening tweet toward the district as a 12 year old San Jose girl.

They are not releasing her name.

The district found out about the tweet on Wednesday and although it didn't threaten a specific school, it did say the person wanted to "shoot up" all of them.

A search warrant was served at the 12 year old's home last night, but she was not arrested.

"One of the things that I know about children, and individuals, and investigations is that we cannot judge until we have all the facts," said Alum Rock Union Elementary School District Superintendent Hilaria Bauer.

Police had been telling district officials and the public they did not believe the threat was credible but they did have a bigger presence on campuses to reassure students and staff.

Bauer says this is a good educational opportunity for families. She said, "An open and honest conversation with our children about this is very, very overdue because they need to know there are consequences. That once you post something, it's out there in the world, and you never know how many people you're going to effect. And that's what happened to us."