An Iranian-American used car salesman from Texas who was at the center of a bizarre plot to assassinate the Saudi ambassador to the United States was sentenced Thursday in federal court in Manhattan to 25 years in prison.

Manssor Arbabsiar, 58, had pleaded guilty in October to a charge of murder for hire and two counts of conspiracy for his role in attempting to orchestrate the 2011 bombing assassination of Adel al-Jubeir while the ambassador dined at an upscale Washington restaurant.

Prosecutors said Arbabsiar was recruited by a cousin who was a senior official in the Quds Force, which the U.S. Treasury Department in 2007 designated a supporter of terrorism. The group is part of the Revolutionary Guard, which is closely aligned with Iranian Supreme Leader Ayatollah Ali Khamenei.

During a trip to Iran in early spring 2011, Arbabsiar's cousin Abdul Reza Shahlai told him that he wanted him to hire someone who could kidnap the Saudi ambassador. Arbabsiar apparently told his cousin and others that he knew people involved in the narcotics business.

Arbabsiar made a number of trips to Iran in 2011 and a plan to assassinate the ambassador evolved. Prosecutors, in arguing for the maximum 25-year sentence, said Arbabsiar understood that any bombing would result in mass casualties but didn't care.

"No big deal," Arbabsiar said when given an estimate of 100 to 150 potential casualties at the restaurant to be targeted, according to the government.