Based on evidence of what he believes is unignited thermite particles in debris collected within minutes after the collapse of the World Trade Center's first tower, retired BYU physicist Steven Jones called for a criminal investigation into the destruction of three World Trade Center high rises in a speech at a 9/11 conference in Boston.  Public video of his presentation at the Decemeber 15, 2007 event was recently released and can be seen here:

 Evidence of Controlled Demolitions