He was portrayed by Patrick Garrow.
Antoine Vallon is a Detroit mobster who was being investigated by Detective Alex Murphy who he killed via a planted car bomb which caused a near-fatal explosion witnessed by Clara and David Murphy. Vallon paid 2 Detroit police officers Andre Daniels and John Lake to keep his operation running smoothly, without police interference, for at least the last 2 years. His chief operation appears to be illegal weapons sales, some of which are retrieved from police evidence lockers.
Alex Murphy and Jack Lewis contacted him through Jerry White, the low-level perp they were doing street-buys from. They met with Vallon, posing as criminals from Chicago who wanted to make a big buy, but Vallon was tipped off, and left, just as a hit squad of three men appeared at the restaurant.
In this shooting, Lewis gets injured, and Lake and Daniels slip Vallon the name of the hospital, in case he wants to take care of Murphy as well. Vallon is hesitant, insisting that if he kills a cop he'll have to look over his shoulder for the rest of his life (somehow overlooking the fact that his last words at the restaurant were "make sure you kill them both"), but takes the bait, sending a henchman to plant the bomb under Alex's car.
Later, he becomes frustrated because with RoboCop on the streets, he can never move any product. Lake and Daniels insist that RoboCop is just a zombie due to his unusual programming and he is safe, but Alex recovers enough of his past to pick up the investigation, determined to end Vallon once and for all, tracking him down through Jerry and Jerry's contact, Vallon's driver, who uses an unencrypted cell phone.
Vallon stages a last stand with all of his men, equipped with high caliber weaponry and night vision goggles, but they are all killed, including Vallon, and Alex takes one of the guns, reading fingerprints of Lake and Daniels on it. It was later revealed that Chief Karen Dean of the Detroit Police Department made a deal with Vallon and covered his tracks which explains why the illegal weapons from the police department's evidence room were stolen.
Antoine Vallon is a mobster who specializes in weapon's illegal dealing. He's rather well organized and has great influence over Detroit, because he has many henchmens at his disposition who are competents enough to cover his tracks, and corrupts cops, including the Chief, who take care of protect him from Murphy. The latters allow him to steal many weapons from the Detroit's Police Department, so he and his mens are very well equipped and dangerous. Because of that, Murphy stuggles to arrest him with sufficients evidences. Vallon is also ruthless toward those who get in his way. This is shown when he discovered Murphy and his partner are cops undercover, he didn't hesitate to order his underlings to kill them in a public restaurant and later, when he learns the cop's identity, he personally approved his assassination, knowing that Lake and Daniels, two corrupts cops, will protect him.
But he's not nearly sadistic or abusive like Clarence Boddicker. In contrast to him, he's much more calm and collected. When one uses his cellphone at his headquarters, inadvertently allowing Murphy to track him, he simply berates him instead of having him killed, which demonstrates he's decent to his henchmens. This was also demonstrated with the two cops Lake and Daniels, questionning them about their duty to protect him. He suggests to the latters to bribe Murphy at first, before ordering the assassination, showing that he prefers non-violent methods and using murder as a last resort. When a Murphy transformed in RoboCop killed all his men and have him at his mercy, he fires at him with his gun before being shot, instead of fleeing or pleading with his life, showing that he was brave.