The mother of a Suffolk County man who was arrested in Penn Station for threatening the Jewish community says her son suffers from mental illness and used to live in a group home.

Police arrested 21-year-old Christopher Brown, of Aquebogue, before midnight Friday in Penn Station. They say Brown was carrying a large hunting knife and had an arm band with a Nazi swastika on it.

Officers also arrested 22-year-old Mathew Mahrer, of Manhattan.

Brown's mother told News 12 Long Island that the two men met at a group home upstate years ago.

The FBI and NYPD joint Terrorism Task Force sent out a flyer internally noting that Brown had allegedly made threats against area synagogues on social media, had a history of mental illness and wanted to obtain a gun.

Detectives later discovered an illegal handgun with a 30-round magazine at Mahrer's apartment.

Brown's mother says her son aged out of a group home in August and has schizophrenia.

“He needs help. We tried to figure out what kind of insurance he has because he was in a group home, and they were no help at all. I wanted to go to the Family Service League with him on Friday and he left,” Kerry Ann Brown said.

She said her son told her he was going to meet a girlfriend in the city.

Kerry Ann Brown said her son has no prior arrests and that, "he is protective, not violent."

"He does things like that to try to shock people," she added.

Police say Christopher Brown tweeted antisemitic threats under the username "Vril-Khan" and told detectives, "I have a sick personality."

Detectives say on Wednesday, Nov. 16, Christopher Brown tweeted a six second video with a message that read, "Brutally murder people with hatchets and whatnot. How it feels to kill people."

Then on Thursday, Nov. 17, detectives say he wrote, "Gonna ask a Priest if I should become a husband or shoot up a synagogue and die."

According to the criminal pomplaint, on Friday Nov. 19, he wrote, "This time I'm really gonna do it."

Kerry Ann Brown said she has not been able to speak to her son since his arrest. She now hopes he will now get the help he needs.

Brown is charged with making a terroristic threat, aggravated harassment and criminal possession of a weapon.

Mahrer faces the same charges.

“A potential tragedy was averted when they were intercepted by police officers at Penn Station, given that online postings indicated an intent to use these weapons at a Manhattan synagogue,” stated Manhattan District Attorney Alvin Bragg in prepared remarks. “Hateful antisemitic targeting of synagogues is deplorable. I am grateful to our law enforcement partners - the NYPD and the FBI - for their quick intervention in apprehending these individuals before they could carry out any attack.”

Mahrer was arraigned around midnight. Court set bail at $150,000 cash or $300,000 bail.

Brown was arraigned Sunday. Bail figures were not immediately available. They are both due back in court on Wednesday.

On Sunday, News 12 Long Island learned that the two arresting MTA officers who helped stop Christopher Brown are from Long Island.

According to the criminal complaint, Officers Ryan Fackner, of North Babylon, and Connor Colasurdo, of Franklin Square, approached both suspects and made the initial arrest.

Manhattan District Attorney Alvin Bragg in a statement shared his appreciation for the joint law enforcement efforts for, "their quick intervention in apprehending these individuals before they could carry out any attack."