A 20-year-old FedEx employee has been arrested in connection with the robbery of one of the company’s delivery trucks in Pleasanton on Wednesday, a police lieutenant said today. Dominique Hamilton, a Union City man who also goes by the name Dominique Fennoy, was arrested after the robbery, which occurred at about 10:45 a.m. Wednesday at a business in the 4300 block of Hacienda Drive. Four suspects wearing masks and hooded sweatshirts confronted the truck driver, a 32-year-old man, as he was making a delivery, police said. One of the suspects took out a shotgun and ordered the driver to open up the truck’s rear cargo area, and the suspects removed several boxes containing computers before fleeing in a gold Buick sedan. No one was injured, police said. The boxes were headed for the Apple Store at the Stoneridge Shopping Center, the truck’s next stop, leading investigators to conclude that the suspects had inside knowledge of the company’s operations, police Lt. Mark Senkle said. Police caught a break in the case because another FedEx driver, who was planning to meet up with the first driver to transfer a package, witnessed the robbery and noted the license plate of the getaway car. With that information, investigators determined it was a rental car and learned it was being driven by Hamilton, who was not the person renting it, Senkle said. Hamilton, who works at the FedEx facility in San Leandro, was arrested when he arrived for work at about 5:50 p.m. Wednesday, Senkle said. He had driven to work in the rental car, and inside the car police found a sawed-off shotgun believed to be the weapon used in the robbery, Senkle said. Hamilton’s duties at the facility, where he has worked for about a year and a half, include loading the delivery trucks on Pleasanton delivery routes, police said. The three other robbery suspects were still at large as of this morning, Senkle said. Police are working with FedEx investigators to determine if any other current or former employees were involved, he said.