The FBI said Kim sent an anonymous e-mail to Harvard officials, campus police, and others at about 8:30 a.m. Monday warning of "shrapnel bombs" in four buildings.

Instead of going home for winter break, 20-year-old Eldo Kim was arrested Tuesday and held overnight on federal bomb hoax charges. He is scheduled to appear in US District Court Wednesday, said US Attorney Carmen M. Ortiz's office.

A Harvard student trying to get out of a final exam admitted to the FBI that he sent a bomb threat that forced the university to evacuate multiple buildings and rattled the campus, federal officials said Tuesday.


"[Be] quick for they will go off soon," the message warned, according to the FBI, which said Kim admitted to adding the word "shrapnel" because it sounded more dangerous.

The threat prompted the university to evacuate three buildings in Harvard Yard — Emerson, Sever, and Thayer halls — as well as the massive Science Center nearby, just as the 9 a.m. exams were beginning. Coming eight months after the Boston Marathon attack, the threat drew a swarm of law enforcement agencies and attracted international attention.

The search for possible explosives disrupted the campus for much of the day and forced a number of exams to be postponed.

According to an FBI affidavit, Kim used a disposable, temporary e-mail address and a temporary Internet Protocol Address to send his warning — with the subject line "bombs placed around campus" — to two university officials, Harvard police, and the student newspaper.

But university officials determined by the end of the day that Kim had used a Harvard wireless network to create the IP, prompting an FBI agent and a campus police officer to interview him in his dorm Monday night.

The agent, Thomas M. Dalton, said Kim admitted to authoring the hoax, picking Emerson Hall, the site of his exam, and three other targets.


Then he walked to his exam. "According to Kim, upon hearing the alarm, he knew that his plan had worked," Dalton wrote in the affidavit.

The bomb-hoax charge under federal law carries a maximum sentence of up to five years in prison, three years of supervised release, and a $250,000 fine.

Harvard officials thanked law enforcement in a statement Tuesday, saying the hoax caused "significant disruption to our campus and a difficult time for many."

"We are aware that a member of our community has been arrested in relation to this matter and are saddened by the details alleged in the criminal complaint," officials said.

Kim's family could not immediately be reached.

On an undated biography on the website for Harvard's Institute for Quantitative Social Science, Kim identified himself as a research assistant helping to analyze "partisan taunting." He also called himself a writer for the Harvard International Review and a dancer with the Harvard Breakers.

In addition, he claimed to enjoy "playing pool, trying new restaurants, watching terrible cult films, and playing with his Mini Schnauzer puppy."

One of the editors in chief of the review, junior Mathilde Montpetit of Boston, said Kim went through an introductory process, writing an article and doing sample editing, as a freshman early last year, then resigned.

Montpetit said that most of her friends quickly assumed the bomb threat was a hoax and that few around her were on edge. But she called it a waste of Harvard time and taxpayer resources.


"I don't know if he deserves five years in prison, but it was definitely stupid," Montpetit said.

Eric Moskowitz can be reached at eric.moskowitz@globe.com.