DANIEL ESTRIN

Associated Press

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.

It was not immediately clear whether that included bomb threats called in last month to JCCs in New Rochelle and Tarrytown.

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 a dual citizen and would remain in custody until at least March 30. During the arrest raid, they said he tried to grab an officer’s gun but was stopped by another officer.

“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.

Local Jewish leaders expressed relief at the arrest.

"We as a community have been shocked by the bomb threats. The bomb threats have taken a serious toll on our communal psyche," said Rabbi Adam Baldachin of Shaarei Tikvah in Scarsdale. "I am relieved today to know that the person that did this has been caught, and that we can go back to our values that we hold dear, which is to protect one another."

Eric Nussbaum, executive director of the Jewish Community Center of Harrison, said the synagogue has always taken such threats seriously and will continue to prepare for them.

"We took synagogue security seriously before these threats started coming, and we'll continue to take them seriously going forward, as well," he said.

"To find out that the perpetrator was someone from within the Jewish community, I think it's hard for people to think about," Baldachin added. "Hatred has no boundaries."

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.

His lawyer, Galit Bash, said her client had a “very serious medical condition” that might have affected his behavior. She said the condition had prevented him from attending elementary school, high school or enlisting in the army, which is compulsory for most Jewish men.

“That’s why the medical condition can actually affect the investigation,” she said. “This is one of the things the judge told the police to check, to talk to his doctors, to get more documents and to investigate him according to his medical situation.”

Channel 10 TV said the condition was a brain tumor. It also showed images of a large antenna outside the suspect’s house in the southern Israeli city of Ashkelon. Police said the suspect’s father was also detained, apparently because of the equipment. Late Thursday, police said the father’s detention had been extended by eight days.

Channel 10 TV said the young man had lived in the U.S. for a period of time and had been home-schooled.

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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.

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 man arrested there 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.

Journal News reporter Matt Spillane, and Associated Press writers Eric Tucker and Sadie Gurman in Washington and Josh Cornfield in Trenton, New Jersey, contributed to this report.