Images of captives - businessmen, foreigners, now a Marine - bandages tightly wrapped around their eyes, have become a chilling and harrowing reality in recent weeks.
The hooded captors say they do it in the name of revenge, but more disconcerting to local Muslims is that these captors tie such violent acts to Islam.
"They are not real Muslims," said Abdul Molla, who was at North Penn Mosque with hundreds of area Muslims taking part in Friday afternoon services last week. "True Muslims would never support this type of killing."
While the recent beheadings of two American businessmen in the Middle East have sparked a backlash against Muslims in some parts of the nation, no anti-Islam signs have been reported in this area.
Nationwide, the murders of Paul Johnson and Nicholas Berg triggered a surge of hate mail and vandalism in the last month, said Ibrahim Hooper, spokesman for the Council on Islamic-American Relations.
"Every day, we get more anti-Muslim hate mail, and we see it spike whenever these kind of incidents occur," said Hooper, of the Washington, D.C.-based organization. "It gets more vicious, when something like this happens. The level of hatred goes way up. There is a visceral reaction. It provokes those who already hold hostilities."
Two mosques in Florida were vandalized in the days after Johnson's killing. In a St. Louis suburb, vandals painted a swastika and the word "Die" on the wall of a mosque. In Texas, dead fish were dumped near the entrance sign to a mosque...