Robert Deguerin

"You did a very, very bad thing, John. You killed Munroe. Now that makes you the mole."

- Deguerin revealing his true colors to Kruger after killing Agent Munroe with Kruger's gun.

Robert Deguerin is the main antagonist in the 1996 action thriller film Eraser. He is a corrupt U.S. Marshal serving as one of the conspirators (alongside his boss U.S. Defense Undersecretary Daniel Harper) behind a scandal to sell rail-guns on the black market.

He was portrayed by James Caan.

Early Life
Deguerin was originally the friend and mentor of John 'Eraser' Kruger (the hero of the film), and he works for the Federal Witness Security Protection Program (WITSEC) as a U.S. Marshal. They used to be close friends until the events of the film.

The Cyrez Scandal
During the beginning of the film, Kruger and the FBI have caught wind of an arms sale formulated by a weapons company called Cyrez Corporation to sell electronic pulse rifles to Russian mobsters lead by the infamous terrorist Sergei Ivanovich Petrofsky for a sum of $52 million, which may lead into a new era of world terrorism. After Cyrez Corporation executive Lee Cullen procure two discs containing the evidence following the suicide of Cyrez CEO William Donahue (who was a major player in the conspiracy), she gives one of the discs to the FBI before Kruger is assigned to protect her by having her to hide in New York City. Kruger is then informed by Deguerin that a certain mole inside the WITSEC that has been murdering several witness and is now targeting Cullen.

True nature and Dock Battle
During a mission to rescue another witness, Deguerin reveals himself as the mole, as he quietly kills the witness. During their trip back home, Deguerin murders WITSEC Deputy Monroe and shows his true nature to Kruger as he attempts to frame the latter for Monroe's death to facilitate his plans further. It is also revealed that Harper is the true mastermind of the arms sale and has secretly stolen the FBI's disc while assigning Deguerin to eliminate Cullen and oversee the incoming shipment at the Baltimore docks. Deguerin also got his two men Agents Schiff and Calderon to murder reporter Claire Issacs under Harper's orders due a phone conversation between Lee and Claire about the scandal. However, Kruger escapes and is now branded as a fugitive alongside Cullen.

While taking a ride in a limousine with Harper and their other conspirator Morehart, Deguerin suggests that they cancel the shipment to avoid any heat from the authorities, but the greedy Harper refuses and threatens to have Deguerin killed if he doesn't finish the job tonight, much to Deguerin's discomfort. Deguerin then suggests laying down a trap at Cyrez, deducing that Kruger and Cullen will head over there to access the disc to prove their innocence and expose the entire scandal. The trap works, as Deguerin manages to capture Cullen while having one of the Cyrez employees to destroy the disc, but Kruger escapes again after killing Cyrez security chief James Haggerty.

Deguerin then brings Cullen to the docks, where he and his men are loading up the gun shipments into Petrofsky's freighter ship. Eventually, Kruger arrives to the rescue with the help from Johnny Castelone (who was previously a mob witness that Kruger saved earlier in the film) and his cousin Tony Two-Toes (who owns the docks). Kruger manages to take down many of Deguerin's men (including Schiff and Calderon) while Johnny, Tony, and their men take down Petrofsky and his men. Kruger then proceeds to save Cullen and expose the rail-guns' presence to the arriving authorities, who then take a critically wounded Deguerin into custody. As a result, Deguerin, along with his co-conspirators, are placed under arrest for their crimes.

Death
The next day, a hearing takes place, but Deguerin, Harper, and Morehart manage to escape charges of treason, since a conviction and sentence for them will not be possible under civil law jurisdiction. As they leave in their limousine, Kruger and Lee are seemingly killed by a vehicle explosion in front of a large crowd of witnesses, including Deguerin himself. As the they drive off, Deguerin convinces Harper to start off a new plot, bragging that he'll kill Lee's family and friends in case they would try to investigate the situation. He believes the explosion had been set up by Harper, but Harper assumed vice versa.

The conspirators soon realize that no one within their inner circle had actually arranged it just as the limousine then suddenly comes to an abrupt halt on a train crossing, and the doors lock themselves shut. The driver, who turns out to be Johnny himself in disguise, exits from the limo and runs off from the area. Deguerin anxiously looks around before receiving a phone call from Kruger, revealing that he and Lee actually faked their deaths to lure the conspirators into a trap. Looking out of the window, Deguerin, Harper, and Morehart see a freight train steadily approaching them and try in vain to escape the limousine. Kruger and Johnny stand by to watch the train smash into the limousine, finally killing Deguerin and his conspirators for good.

Trivia

 * Deguerin was thought to be the main antagonist of the film as he was the one who drove the plot of the film by acting as Kruger's direct threat, but it turns out that he was answering to Harper the entire time, even getting uncomfortable when Harper threatened to have him killed if he didn't finish up the job in selling the rail-guns.