The petition cites many sources of hard evidence, beginning with two scientific papers claiming thermite (an incendiary) and nano-thermite (an explosive) have been found in the WTC dust. According to Activist Post the evidence cited is as follows:

From Architects for 9/11 Truth:

According to the 52-page petition, which is accompanied by 57 exhibits, federal statute requires the U.S. Department of Justice to relay citizen reports of federal crimes to a special grand jury. The unprosecuted crime alleged to have taken place on 9/11 is the bombing of a place of public use or a government facility — as prohibited under the federal bombing statute or 18 U.S.C. § 2332f — as well as a conspiracy to commit, or the aiding and abetting of, said offense…

Lawyers’ Committee Executive Director Mick Harrison expressed “cautious optimism” that the U.S. Attorney would fulfill his mandatory duty to present the reported evidence to a grand jury, his optimism based on the fact that the law offers the U.S. Attorney no discretion in whether to do so. However, in the event the U.S. Attorney does not bring forth the evidence to a grand jury, Mr. Harrison said, the petitioners reserve the option of bringing a mandamus action in federal court. A mandamus action, if successful, would compel the U.S. Attorney to fulfill his legal obligation.