Supposedly the death threat was issued by this group:
Revolution Muslim, a hate group out of Franks area..
Wikipedia:
Revolution Muslim is a radical Islamist organization and movement based in New York City that advocates the re-establishment of a structured Islamic state, terrorism both in the United States and in democratic countries around the world, the removal of the current rulers in heavily Muslim populated nations, the destruction of Israel, and an end to what they consider "western imperialism".
They operate both on its website and through street preaching and protests, mostly outside the Islamic Cultural Center of New York.[1][2]
Why can't the FBI go in and arrest the whole lot of them for death threats? The evidence is easy to glean.