Last Updated Oct 17, 2012 2:08 PM EDT
Updated at 2:08 p.m. ET
NEW YORK A Texas man pleaded guilty Wednesday to plotting to assassinate Saudi Arabia's ambassador to the United States, agreeing to hire what he thought was a drug dealer in Mexico last year for $1.5 million to carry out the attack with explosives at a Washington restaurant.
Manssor Arbabsiar, 58, entered the plea to two conspiracy charges and a murder-for-hire count in U.S. District Court in Manhattan, where Judge John F. Keenan repeatedly asked Arbabsiar whether he intended to kill the ambassador. Arbabsiar, a U.S. citizen who holds an Iranian passport, said he did.
A U.S. official previously confirmed to CBS News correspondent Bob Orr that Arbabsiar would enter his plea a little more than a year after being arrested in the plot that the Obama administration said involved Iranian agents.
Sentencing was set for Jan. 23, when Arbabsiar will face up to 25 years in prison. A trial had been scheduled for January.
At the plea, Assistant U.S. Attorney Edward Kim asked Arbabsiar if officials in the Iranian military were involved in the plot. Arbabsiar said they were.
Arbabsiar, who lived in Corpus Christie, Texas, for more than a decade, said he went to Mexico last year to meet a man named Junior, "who turned out to be an FBI agent." He said that he and others had agreed to arrange the kidnapping of the ambassador, Adel Al-Jubeir, but Junior said it would be easier to kill the ambassador.
Arbabsiar has been held without bail since he was arrested Sept. 29, 2011, at John F. Kennedy International Airport. He was brought into court Wednesday in handcuffs. He spoke English and did not use a translator, despite saying he understood only about half of what he read in English. Bearded and bespectacled, he smiled several times during the proceeding, including in the direction of courtroom artists who were seated in the jury box when he entered court.
Defense lawyers say Arbabsiar suffers from bipolar disorder.
Kim said that if the government had proceeded to trial, it would have presented a jury with secretly recorded conversations between Arbabsiar and a confidential source, along with Arbabsiar's extensive post-arrest statement to authorities and emails and financial records.
Arbabsiar was charged along with Gholam Shakuri, who authorities said was a member of Iran's special operations unit known as the Quds Force.
According to a criminal complaint filed in federal court, Arbabsiar said his cousin, Abdul Reza Shahlai, was a high-ranking member of the Quds Force who asked for his cooperation. Arbabsiar said he frequently traveled between the U.S. and Mexico for work and knew people he believed were in the drug trade, and his cousin asked him if he could recruit someone in the narcotics business for criminal activity.
In a statement, Mary Galligan, acting assistant director of the FBI, hailed Arbabsiar's plea:
"Mr. Arbabsiar's plea today confirms what our investigation had already uncovered: That he plotted to murder the Saudi ambassador with members of Iran's elite Quds Force. Not only did this plot threaten the ambassador's life, the planned attack targeted our nation's capital, where innocent lives would have been lost and the national psyche damaged. Others who believe that they can carry out or even attempt to plan such brazen plots should be on notice: The FBI remains ever vigilant towards acts of terror both here and abroad."
Authorities have said they secretly recorded conversations between Arbabsiar and an informant with the Drug Enforcement Administration after Arbabsiar approached the informant in Mexico and asked his knowledge of explosives for a plot to blow up the Saudi embassy in Washington. They said Arbabsiar later offered $1.5 million for the death of the ambassador.
Arbabsiar admitted Wednesday that he eventually made a $100,000 down payment wired from an overseas account through a Manhattan bank.
The complaint describes the informant as someone who was previously charged for violating drug laws in the United States but got the charges dismissed by agreeing to cooperate with U.S. drug investigations. U.S. officials trusted the informant because he had proved reliable in the past and led to several drug seizures -- and the informant was paid for those tips.
According to transcripts of their recorded conversations cited in the complaint, the informant told Arbabsiar he would kill the ambassador however he wanted -- "blow him up or shoot him" -- and Arbabsiar responded he should use whatever method was easiest. The plot eventually centered on targeting Al-Jubeir in his favorite restaurant and Arbabsiar was quoted as saying killing him alone would be better, "but sometime, you know, you have no choice." Arbabsiar dismisses the possibility that 100-150 others in the restaurant could be killed along with the ambassador as "no problem" and "no big deal."
Eventually, according to the complaint, the informant told Arbabsiar he must come to Mexico to offer himself as "collateral" for the final payment of the $1.5 million fee for the assassination. Arbabsiar said Shakuri, his cousin's deputy at the Quds Force, warned him against offering himself as a guarantee of payment. But Arbabsiar went anyway, boarding a flight to Mexico Sept. 28, 2011, with plans to fly to Iran after the plot was finished.
Mexican authorities, who said they had been cooperating with U.S. officials in the investigation, denied Arbabsiar entry into the country and he boarded a flight to New York's John F. Kennedy International Airport. Law enforcement officials secretly boarded with him to keep him under surveillance, and he was arrested when he got off the plane in New York.
Arbabsiar agreed to cooperate with U.S. authorities and made several recorded phone calls to Shakuri in which they discussed the purchase of a "Chevrolet," their agreed-upon code-word for the plot. Shakuri urged Arbabsiar to make sure they "just do it quickly."