The FBI is seeking a warrant to obtain his online accounts and were scouring digital evidence, the official said. Former New York Assembly member Dov Hikind said the state's Jewish residents are "sick and tired" of tweets condemning anti-Semitism and want concrete steps to prevent more violence. Authorities have not provided a motive.
The stabbings come on the heels of a string of attacks targeting Jews in the region.
"Let's call it what it is".
Police apprehended Grafton without incident after midnight, a New York Police Department spokeswoman told CNN earlier Sunday.
Police said the stabbings happened at around 10 p.m. Hours later, Brad Weidel, the police chief for the town of Ramapo, which covers Monsey, said that New York City police had located a vehicle and a possible suspect sought in connection with the attack.
An ambulance worker was filmed running a stretcher down the road near the house.
Grafton tried to enter the synagogue next door but it was already barricaded by people who had taken shelter inside.
"He had something in his hand".
"I saw him stabbing people", he added.
Police will increase visits to houses of worship and "other critical areas in the community", he said.
In more deadly recent attacks, a gunman killed a female rabbi and wounded three people during Sabbath services in San Diego in April, while a gunman shot and killed 11 worshipers at a Pittsburgh synagogue in October 2018.
His vehicle registration was passed to police and license plate scanners picked up the auto as it entered New York City, where he was detained in the Harlem area. Reports said he was arraigned this morning and pleaded not guilty.
Thomas played football for two seasons at William Paterson University in New Jersey.
The suspect was identified by police as a local man from Greenwood Lake, New York. No one answered a telephone number listed for his address and the voicemail box was full.
"We must work together to confront this evil, which is raising its head again and is a genuine threat around the world".
"Enough talk, it is time for action to deter those who propagate this hatred", Israeli Ambassador Danny Danon said.
In the most violent incident, four people were shot and killed in nearby Jersey City in an anti-Semitic attack that targeted a kosher deli on December 10.
At least five people, all Jewish, were taken to hospital with stab wounds, the council said. It's unclear whether the assailant has been arrested.
Mayor Bill de Blasio said on Friday that the police presence would be increased in Brooklyn neighbourhoods with large Jewish populations. "I've spoken to longtime friends who, for the first time in their lives, are fearful to show outward signs of their Jewish faith". "No one should have to live like this".
After the attack, four Orthodox Jewish elected officials - State Senator Simcha Felder, State Assemblymember Simcha Eichenstein, New York City Councilmember Chaim Deutsch, and New York City Councilmember Kalman Yeger - submitted a letter to Cuomo asking him to declare a state of emergency and deploy State Police and the New York National Guards to protect Orthodox neighborhoods.
New York Governor Andrew Cuomo outside the house.