Terrorist Death Penalty Enhancement Act of 2005

Terrorist Death Penalty Enhancement Act of 2005 - Amends the federal criminal code to apply the death penalty or life imprisonment for a terrorist offense that results in the death of a person. Makes an individual or corporation convicted of a terrorist offense ineligible for federal benefits for any term of years or for life.

Amends the Violent Crime Control and Law Enforcement Act of 1994 to make the death penalty available in certain air piracy cases occurring before enactment of the Federal Death Penalty Act of 1994 but after enactment of the Antihijacking Act of 1974. Narrows the language of "especially heinous, cruel, or depraved" by requiring that the act involved torture or serious physical abuse to the victim.

Includes among aggravating factors for espionage, treason, and terrorism for which the death penalty may be imposed that the defendant committed the offense after substantial planning. Authorizes imposition of the death penalty for specified terrorism-related offenses, including an offense involving the use of a radiological dispersal device or the variola virus.

Modifies death penalty procedures, including by adding as an aggravating factor for homicide for which the death penalty may be imposed that the defendant engaged in any conduct resulting in the death of another person in order to obstruct the investigation or prosecution of any offense. Authorizes impaneling a new jury when a unanimous recommendation cannot be reached. Permits four additional peremptory challenges when seven, eight, or nine alternates are impaneled.