The man appeared to be some type of supercriminal - a drug-dealing, gun-running member of the Sicilian Mafia who held up cigarette trucks, fingered enemies for assassination and swam in millions of dollars that needed laundering.

He became, authorities allege, a trusted go-to guy and moneymaker for associates of the Ghee Kung Tong, the Chinese brotherhood that Raymond "Shrimp Boy" Chow ran in San Francisco's Chinatown.

Or so everyone thought.

The man Chow had called a "good brother" was actually an FBI agent now known in court records as "UCE 4599," short for undercover employee. All the bravado about underworld connections was part of an elaborate cover story - or legend, in FBI parlance.

It was the work of this and other undercover agents, the FBI said, that led to federal charges against 26 people, including Chow and state Sen. Leland Yee. Chow is accused of crimes including money laundering, while Yee is accused of conspiring to traffic in guns (with the agent) and of trading political favors for campaign donations (from multiple undercover agents).

Since Yee's arrest Wednesday morning, which prompted him to drop his bid to be elected secretary of state, much of the focus has been on his alleged willingness to accept bribes.

But the case is also striking for the lengths to which UCE 4599 went to cast himself as a bad guy, doling out streams of cash and boasting that "the only license he had was to do whatever business he wanted to." The agent was so effective, the FBI said, that he was "sworn in" to the Ghee Kung Tong.

A target for defense

The agent's aggressiveness, while not unusual in federal probes of organized crime and terrorism, may become a target for defense attorneys, who often argue in such cases that none of the alleged crimes would have occurred if they weren't initiated by the FBI.

In any event, UCE 4599 succeeded in his primary objective: keeping his cover. At one point, when one of the defendants voiced suspicions about the agent, Chow responded that if the man "was a snitch, he was a very good one," according to an FBI affidavit.

The depths to which the agent and others infiltrated the group must have required them to live and breathe their personas around the clock, said Rick Smith, a former FBI special agent in San Francisco who now works as a private investigator.

New home, new identity

He said the agents most likely had to live in new homes away from their families and center their lives on entirely new - and convincing - identities, both in real life and on social media, in case targets smelled a rat and started investigating.

The case has parallels with the recent indictment of state Sen. Ron Calderon, D-Montebello (Los Angeles County), on corruption charges. Calderon is accused of accepting tens of thousands of dollars in bribes from undercover FBI agents who posed as Hollywood film studio executives who wanted him to support a film tax credit.

'Living that life'

"A lot of acting is involved," Smith said of undercover work. "They wouldn't be doing this on a part-time basis. You're living that life for a while. You start from scratch, and you assume a new identity."

The agents in the San Francisco case were likely given the authority from higher-ups at the FBI to engage in crime in order to snare the targets.

"There is a fine line," Smith said, adding that the FBI scrutinizes such operations to counter any defense claims of entrapment. "That's absolutely anticipated, and they'll deal with it when they have to deal with it."

Although other federal agencies have been known to ship in undercover officers from different parts of the country, Smith said it was more likely that the FBI "used someone local" because "you want someone indigenous, because they know the community."

As for the cash and contraband that the FBI distributed during the Chow investigation, Candice DeLong, a former FBI profiler, said the bureau often has "stuff that is seized," such as money or drugs, that can be tapped.

"You can't work undercover and expect to make a case," DeLong said, "without coming up with the goods."

Agent met with targets

Court records reveal how UCE 4599 and other undercover FBI agents sought to draw out Chow, Yee and the others.

Chow was first introduced to UCE 4599 in May 2010, when the agent claimed to be with La Cosa Nostra. The agent later met with targets all over the Bay Area and elsewhere, including Las Vegas and Flushing, N.Y., records show.

Eventually, the FBI said, Chow and five other defendants laundered $2.3 million for UCE 4599, who told the men that the money came from illegal gambling and marijuana grows. The agent forked over a 10 percent commission, the FBI said.

The undercover agent stayed busy, either initiating or participating in deals to traffic in illicit liquor, cigarettes, guns and drugs, and asking some of the targets to kill people, FBI Special Agent Emmanuel Pascua wrote in an affidavit.

Pascua said the agent ultimately made contact with Yee through an associate who helped Yee raise money, including for his failed 2011 San Francisco mayoral campaign. Yee allegedly agreed to trade favors in Sacramento for campaign contributions made by UCE 4599 - as well as agents UCE 4773 and UCE 4180.

It was UCE 4599 who reported engaging in a gun-trafficking deal facilitated by Yee, again while offering campaign funds.

"Senator Yee told UCE 4599 he saw their relationship as tremendously beneficial," Pascua wrote in his affidavit.

Yee, he said, promised to name the agent to a Russian delegation upon winning the election for secretary of state.
