A former FBI agent convicted of planning an invasion-style robbery of what he thought was a drug stash house containing a half-million dollars in cash was sentenced to 30 years in prison Monday by a federal judge in Santa Ana.

Ex-agent Vo Duong Tran, 42, and his accomplice, Yu Sung Park, 36, were arrested in possession of bulletproof vests, a machine gun, other weapons, silencers and hundreds of rounds of ammunition that they intended to use to rob the supposed drug house in Fountain Valley, a jury found.

In reality, the “stash house” did not exist. It was created as part of a law enforcement sting operation. During the probe, Tran and Park were secretly recorded planning the details of the would-be caper with an undercover federal agent and an informant.

Tran and Park told the agent and informant to use one of the drug dealers inside the house as a “human shield” to clear the location and to shoot anyone who did not follow instructions.

In a reference to the machine gun, Tran, an 11-year FBI veteran, boasted that he could “take out five cops in a second” if any officers responded to the scene during the robbery, according to court papers.

Recordings of those and other statements were played for jurors during a month-long trial before U.S. District Judge Andrew J. Guilford last year.

Tran’s attorney, Alex R. Kessel, argued at trial that despite having been fired by the FBI years earlier, Tran remained loyal to law enforcement. He said Tran was only pretending to be a criminal because he was conducting his own undercover investigation and planned to go to authorities with the results.

The jury, which deliberated for one day, rejected that explanation. Jurors found Tran and Park guilty of conspiracy to obstruct commerce by robbery, interstate travel to commit a crime with a firearm and possession of a machine gun.

Though they were not charged with any actual robberies, both Tran and Park admitted having committed “similar home-invasion style robberies of drug dealers in the past,” according a sentencing memorandum filed by prosecutors.

Tran was hired by the FBI in 1992 and assigned to the Chicago field office. He was suspended nine years later after admitting to a bureau security officer that he attempted to bribe a Vietnamese official for information while on a personal trip to Vietnam, according to court records unrelated to the Orange County case. While on suspension, he was charged by prosecutors in Illinois with impersonating a peace officer after he allegedly identified himself as an FBI agent to a family he said was being targeted for a home invasion robbery. He was acquitted of those charges in court.

Tran was fired from the FBI in April 2003. A little more than a year later he was indicted by federal prosecutors in Atlanta on charges that he obtained firearms and silencers by falsely stating that he was a resident of Georgia and that he needed the items in connection with his work for the FBI. The government dismissed the case after a judge ruled that evidence seized from Tran’s apartment in Chicago was inadmissible.

In the case for which he was sentenced Monday, Tran traveled from his home in Louisiana to Southern California to commit the robbery. He and Park, who was also sentenced to a 30-year prison term, were arrested by an FBI SWAT team in July 2008 in the parking lot of an Orange County hotel.

scott.glover@latimes.com