The husband of a teacher found dead in her Staten Island home in July was arrested and charged Tuesday with murder and criminal possession of a weapon.

Police believe Jonathan Crupi, 30, is responsible for the death of his wife Simonette Mapes-Crupi, who was discovered stabbed to death on July 5.

The Staten Island District Attorney's office says Jonathan Crupi was taken into custody at his mother's house on Tuesday.

The husband and wife both taught at the School For Classics in Brooklyn.

Jonathan Crupi is on a leave of absence.

The Department of Education says a crisis team has been brought in to talk with upset students.

Mapes-Crupi's mother, Theresa Mapes, said she doesn't know why her daughter was killed.

She said the couple was madly in love and rarely fought.

"We don't know how it occurred," Theresa Mapes said. "We don't know what caused it, so there's no closure as of yet. And like I said, it's kind of hard to believe it's my son in law."

Crupi has maintained his innocence.

He is expected to be arraigned Wednesday.