A man who allegedly threatened a school attack in California that would dwarf the Virginia Tech attacks turned himself in, ending a manhunt that prompted school districts in two cities to tighten security, authorities said.
Several schools canceled classes or evacuated students Thursday and at least a dozen people were arrested or under investigation as a wave of campus threats that started soon after the Virginia Tech shootings spread across the country.
In Yuba City, a 28-year-old man told a pastor Wednesday night that "he had some sort of explosive device and he was going to make the incident at Virginia Tech look mild by comparison," Sutter County Sheriff Jim Denney said.
The man surrendered without incident at the sheriff's department around 9:30 p.m. Thursday, shortly after his parents called authorities to tell them he would turn himself in, Denney said. The man was booked on suspicion of making criminal threats and making felony threats while on bail on a previous charge.
Officials canceled classes and activities for Friday at school districts in Yuba and Sutter counties and at Yuba College. Yuba City is about 35 miles (55 kilometers) north of Sacramento.
Nationwide, many of the threats - which spread in the time it takes to make a phone call or post a message on the Internet - referred to Monday's massacre in Blacksburg, Virginia, in which gunman Cho Seung-Hui killed 32 people and himself, or the 1999 Columbine High School killings in Colorado, authorities said. Friday is the eighth anniversary of the Columbine attacks.
In San Diego, a Web designer was charged with posting on his own site a bogus threat to kill 50 San Diego State University students, then alerting a TV station to try to draw publicity, the FBI said.
Cristobal Fernando Gonzalez, 32, is charged with one felony count of making a threatening communication through the Internet. He was being held on $30,000 (euro22,057) bail.
His parents said outside the federal courthouse that he was remorseful. "I hope it doesn't ruin his future," said his mother, Diana Gomez.
In Commerce City, Colorado, a Denver suburb about 190 miles (306 kilometers) from Columbine, a 13-year-old boy stood up in class and said he had a bomb, forcing the evacuation of Kearney Middle School and the lockdown of 13 other Adams County schools, district spokesman John Albright said.
"In his personal effects we found duct tape, a bicycle pump and a couple things that were potentially suspicious," Albright said. "And in his locker they found a box all duct-taped up."
The boy was taken into custody and he told police where they could find "the bomb," which turned out to be a fake, police said.
In Michigan, police said they arrested a former Kalamazoo Valley Community College student who posted Internet messages praising the Virginia Tech shooting. Officials closed the college's two campuses through the weekend.
The 26-year-old man "said his intent was just to evoke a response from other people," sheriff's Lt. Terry VanStreain said. "He got a response from us, I guarantee you that."
Classes at the University of Nevada, Reno, were canceled Thursday night after police received reports that a man made threats referencing the Virginia Tech shootings. Michael James Sheriff, 27, was arrested in Carson City on a probation violation related to a conviction for carrying a concealed weapon.
Officials said Sheriff sent a text message Thursday to a relative saying "the Korean is my hero." He also allegedly told another relative Wednesday that he would be unavailable for the next few days because he would be on a "mission," police said.
Family members contacted authorities expressing concern about Sheriff, who served in the Iraq war and had been treated for post traumatic stress disorder and mental illness, police said
In Camarillo, California, a student at California State University, Channel Islands, was arrested after a fellow student reported seeing a note on her Facebook.com page that said she planned a "school shooting spree."
Alisha Salazar, 18, was booked for investigation of making criminal threats and was being held at the Ventura County Jail on $20,000 (euro14,705) bail, authorities said.
School officials said her online message read: "Alisha Salazar is going on a ... school shooting spree! Watch out kiddies, better hide under that desk! hahaha," the statement said.
Campus police questioned Salazar and searched her dormitory room before transferring her to sheriff's custody, said campus spokeswoman Ceal Potts.
Salazar's statements to police were not released, and it was not known whether she has retained an attorney, Potts said.
Among other arrests and school scares Thursday:
_ A high school student in Federal Way, Washington, near Seattle, was arrested after authorities said he brought three loaded guns and extra ammunition.
_ A 20-year-old man in Bismarck, North Dakota, was charged with saying on a blog that the Virginia Tech massacre was funny and that he had plans for a school shooting rampage.
_ A high school student in Fort Smith, Arkansas, was arrested after police said he scrawled a message on a classroom desk saying he wanted to "be a hero" like Cho.
_ In St. Augustine, Florida., a 14-year-old high school student was charged with threatening in an e-mail between friends to top the Virginia Tech massacre by killing 100 people, a sheriff's spokesman said.
Associated Press Writers James Prichard in Kalamazoo, Michigan, and Oskar Garcia in Omaha, Nebraska, contributed to this report.
