Last of two parts. The leader of the local Islamic organization preparing to build a major new mosque in Boston is allegedly linked to a network of Muslim companies and charitable groups in Virginia suspected by federal investigators of providing material support to Islamic terrorists. The chairman of the board of trustees of the Islamic Society of Boston, which has city approval to construct a $22 million cultural center and mosque in Roxbury, was also a leader of an Indiana-based Muslim organization known for its anti-Western rhetoric and for providing a platform for radical Islamists, some of whom have been...