The gruesome and unsolved murder of a Coptic family in Jersey City, New Jersey, has created anger and anxiety among Copts in this multiethnic community, just a few miles from New York City.

Copts fear that Muslims may have brutally murdered Hossam Armanious, 47, his wife, Amal Garas, 37, and their two daughters, Sylvia, 15, and Monica, 8, on January 14. Police discovered the bodies of the four family members bound and stabbed repeatedly, with their throats slit. Police are investigating whether the grisly incident was motivated by robbery or religious hatred.

In weeks prior to the killings, Hossam, described as a fervent Copt, had passionately debated Muslims in internet chat rooms. Copt leaders say he received an online anonymous death threat for proselytizing and for discussing the persecution of Christians in Egypt by Muslims.

Personally, I hope it was not Muslims who did this," Emad Fahmy, Amal Garas's brother-in-law, told CT. "But I ask myself, What else would motivate someone to do this?"

Police are investigating robbery as one potential motive, because the pockets of all the victims had been emptied and the family ATM card used. But Michael Meunier, president of the U.S. Copts Association, notes that the family wasn't rich and that several pieces of jewelry, including a diamond ring, were not stolen from the home. "These were vengeful killings," he said.

Local Muslims expressed grief. "We have full sympathy for the family," said Chatha Arshad, president of the Muslim Federation of New Jersey, in Jersey City. "It is unimaginable what happened. We condemn it from the whole of our heart."

Osama Hassan, director of the Islamic Center of Jersey City, doesn't believe Muslims are responsible. And he believes that if he's wrong, ...