The alleged plot to assassinate the Saudi ambassador to the United States seemed as convoluted as it was coldblooded, involving an effort by the Iranian government to recruit a Mexican drug cartel to kill the envoy in Washington.

But the main suspect in the case, a 56-year-old Iranian American named Mansour Arbabsiar, was peculiarly positioned to advance such an elaborate plot, according to U.S. officials and court filings.

Arbabsiar spent years in the United States but had connections with elements in Iran’s military, including a cousin who served in the country’s Quds Force, an elite unit accused of terrorist attacks and assassinations abroad, according to the Justice Department. The cousin, identified in a Treasury Department release as Abdul Reza Shahlai, worked with another member of the force, Gholam Shakuri, who was also charged in the plot.

Because Arbabsiar lived in Texas and had frequent business across the border in Mexico, he had come to know other travelers who he believed were narcotics traffickers and possibly capable of carrying out a high-profile hit, the complaint filed by the Justice Department said.

Arbabsiar appears to have operated small auto sales outfits in Corpus Christi as well as a restaurant, according to public records, and earlier this year he began carrying on coded conversations with handlers in Iran. At one point, U.S. officials allege, he signaled that the plot would proceed by telling his contact, “The Chevrolet is ready, it’s ready, uh, to be done.”

This undated image provided by the Nueces County Sheriff's Office shows Mansour Arbabsiar. (Anonymous/AP)

David Tomscha, 60, met Arbabsiar 15 years ago when he bought an Acura Integra from him in Corpus Christi and later bought a car lot with him. Tomscha described Arbabsiar as a disorganized businessman who often could not locate the titles of cars he was selling. Tomscha eventually bought Arbabsiar’s half of the business after he failed to pay his bills. “I would say he did it for the money,” Tomscha said, referring to the allegations against him. “He’s not a terrorist. He’s more an opportunist than anything else.”

Neighbors offered conflicting characterizations of Arbabsiar. A neighbor in Round Rock, Tex., said that news vans were parked in front of Arbabsiar’s stucco house on a cul de sac on Tuesday; ordinarily, the family keeps to itself. “Those folks were not real friendly,” said Caryl Lowe, a neighbor.

Anita Saenz, who lived in the same condominium complex as Arbabsiar before he moved from Corpus Christi, recalled his used-car sales shop on South Staples Street and said he had separated from his first wife. “He was always laughing and seemed like he was a nice guy,” she said.

Arbabsiar, known by some as “Jack,” had minor brushes with the law. He was arrested in 2004 for driving with an invalid license and was convicted of a lesser charge, records show. In 2001, he was accused in a check-fraud case, but the charge was later dropped.

In the late 1980s, he was the target of a protective order filed in Texas by his ex-wife, Esperanza, according to records from their divorce.

Arbabsiar, who has at least two children, gave no outward indication that he cared about long-simmering frictions between Iran and Saudi Arabia. U.S. officials said he may have been selected largely because he was unlikely to have raised suspicions among American authorities.

Even so, the criminal complaint portrays him as enthusiastically committed to the alleged plot.

The efforts failed, U.S. officials said, largely because Arbabsiar thought he was enlisting the help of the notorious Los Zetas drug cartel when in reality he had come into contact with an informant for the Drug Enforcement Administration.

In a July 17 meeting with that informant, Arbabsiar made it clear that the assassination was to proceed even if it meant mass casualties, according to the Justice Department filing.

“They want that guy done,” Arbabsiar said, referring to Iran’s interest in killing the ambassador, according to the filing. “If the hundred go with him, [expletive] them.”

Arbabsiar is accused of making repeated trips between Iran and Mexico and arranging money transfers totaling nearly $100,000 from Iran as the down payment on an assassination that carried a price tag of $1.5 million.

When the informant, posing as a cartel operative, demanded more money up front, Arbabsiar said he was willing to travel to Mexico, offering himself as collateral to the cartel, until the killing was done.

Last month, Arbabsiar flew to Mexico but was denied entry and sent back to the United States. U.S. law enforcement officials kept him under surveillance throughout the flight. When the plane landed at John F. Kennedy International Airport in New York, Arbabsiar was arrested. He had $3,900 in American cash, Iranian currency, an Iranian passport and travel documents indicating that he planned to depart Mexico in October “with an ultimate destination of Iran.”