El Camino High School in Rohnert Park was locked down for more than an hour Tuesday morning after a student reported that a relative had made "death threats," Rohnert Park authorities said.
The campus shutdown was lifted after police contacted the alleged suspect, who was arrested after meeting with officers and detectives at the police station, Lt. Jeff Taylor said.
The suspect, identified as Shelby Wilcox, 19, was arrested on suspicion of making criminal threats and taken to county jail, police said.
The episode began when the student, a minor who was not named, went to the school office and reported the threats about 9:10 a.m.
The school principal locked down the campus, preventing anyone from entering or leaving, and keeping students, faculty and staff in their classrooms and offices, Taylor said.
Police began searching for Wilcox and eventually reached her by cellphone, he said. The lockdown was lifted about 10:26 a.m. after Wilcox was arrested.