The father of subway terror plotter Najibullah Zazi faces additional charges for his alleged attempts to cover up his son's crimes. The additional counts include obstruction of justice, witness tampering, and making false statements to the FBI.

According to federal prosecutors, Mohammed Wali Zazi was more involved in his son's plot against the New York City subway than previously disclosed. During the course of their investigation, federal investigators spoke with Zazi about his son's involvement in the case and the role that a local Imam may have had in tipping off the conspirators.

Zazi allgeedly lied to law enforcement officials about his contacts with both his son and Imam Afzali. He also allegedly destroyed evidence, including masks, chemicals, and other objects related to the plan to construct explosive devices for deployment throughout the subway system.

In February, Najibullah Zazi pled guilty to masterminding the plot and has since been cooperating with law investigators. His co-conspirator, Zarein Ahmedzay pled guilty in April of conspiracy to use weapons of mass destruction, conspiracy to commit murder in a foreign country, and providing material support to a terrorist organization—namely al Qaida. Imam Afzali pled guilty to tipping off Najibullah Zazi. Following his plea, Afzali was deported.

The superseding indictment follows obstruction of justice charges filed in January. Zazi pled not guilty to those charges and is scheduled to appear in federal court on December 9 to be arraigned on the new charges.