JERUSALEM --Israeli police on Thursday arrested a 19-year-old Israeli Jewish man as the primary suspect in a string of bomb threats targeting Jewish community centers and other institutions in the U.S., marking a potential breakthrough in the case after an international manhunt with the FBI.
Police spokesman Micky Rosenfeld described the suspect as a hacker, but said his motives were still unclear. Police banned publication of his name, but said he was an American-Israeli dual citizen and that he would remain in custody until at least March 30.
"He's the guy who was behind the JCC threats," Rosenfeld said, referring to the dozens of anonymous threats phoned in to Jewish community centers in the U.S. over the past two months. Israeli media said the man had been found unfit for compulsory military service.
Israel's Channel 10 TV showed footage of the suspect appearing in court in the central Israeli city of Rishon Letzion. He wore tan pants and a blue sweater that he used to cover his face as he walked past reporters.
MORE: FBI makes arrest in Jewish community center threats
The channel said the young man had lived in the U.S. for a period of time and had been home-schooled. It showed images of a large antenna outside his house and said his father was also arrested.
In Washington, the FBI confirmed the arrest of the main suspect.
U.S. Attorney General Jeff Sessions said the arrest was the result of a large investigation into hate crimes against the Jewish community. He said the Justice Department "will not tolerate the targeting of any community in the country on the basis of their religious beliefs." He called work by the FBI and Israeli police "outstanding."
The Anti-Defamation League, a Jewish-American group that battles anti-Semitism, says there have been more than 150 bomb threats against Jewish community centers and day schools in 37 states and two Canadian provinces since Jan. 9. Those threats led to evacuations of the buildings and raised fears of rising anti-Semitism. The threats were accompanied by acts of vandalism on several Jewish cemeteries.
President Donald Trump's administration was criticized for not speaking out fast enough. Last month, the White House denounced the threats and rejected "anti-Semitic and hateful threats in the strongest terms."
Jonathan Greenblatt, the chief executive of the ADL, expressed relief over the arrest and thanked the FBI and U.S. authorities for making the investigation a priority.
"Even though it appears that the main culprit behind the majority of these attacks has allegedly been identified, anti-Semitism in the U.S. remains a very serious concern," he said, noting there have been no arrests in other anti-Semitic incidents. "JCCs and other institutions should not relax security measures or become less vigilant," he said.
Jordan Shenker, the head of one of the targeted community centers, said he was relieved to hear of the arrest, and was hopeful that the suspect had acted alone.
"Certainly if that is confirmed, there will be a far greater sense of relief and comfort on behalf of all of our members," said Shenker, head of the Kaplen JCC on the Palisades in Tenafly, New Jersey, a New York suburb.
U.S. authorities have also arrested a former journalist from St. Louis for allegedly threatening Jewish organizations. Juan Thompson has been indicted in New York on one count of cyberstalking.
But Israeli police described the local man as the primary suspect in the wave of threats.
Israeli police said the suspect made dozens of calls claiming to have placed bombs in public places and private companies, causing panic and "significant economic damage," and disrupting public order, including by the hurried evacuations of a number of public venues around the world. The man is also suspected of placing threatening phone calls to Australia, New Zealand and also within Israel.
Rosenfeld said the man called Delta Airlines in February 2015 and made a false threat about explosives aboard a flight from JFK airport in New York. The threat allegedly led to an emergency landing.
Yaniv Azani, an official in the Israeli police's cyber unit, said the suspect had used sophisticated means to cover his tracks.
"He used several different means to camouflage the various layers of communication mechanisms he used to carry out these calls," he told reporters.
Rosenfeld said the man, from the south of Israel, used advanced technologies to mask the origin of his calls and communications to synagogues, community buildings and public venues. He said police searched his house Thursday morning and discovered antennas and satellite equipment.
Israeli cybersecurity expert Nimrod Vax said the phone calls required a certain level of sophistication, but were "not too difficult" for an experienced hacker.
"It's not something anyone from the street could do. But it doesn't take any expensive, or resources that are hard to get, to build this kind of an attack or diversion," he said.
He said tracking down the suspect was far more challenging, requiring authorities to go through "billions, if not trillions" of records, including phone records, routing logs and IP connections.
"This takes a processing of a lot of data, so it requires a lot of resources," said Vax, a co-founder of Israeli-U.S. cybersecurity company BigID.