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 the two men met at a group home upstate years ago.

The FBI and NYPD joint Terrorism Task Force sent out a flier 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,” says Kerry Ann Brown.

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

Mahrer faces the same charges.