A Suffolk County grand jury has charged the man East Hampton Town police charged with drunken driving after a collision on Montauk Highway on Napeague in June that sent a motorcyclist to the hospital with critical injuries. The charge, assault by recklessly causing serious injury with a weapon (his 2013 BMW), is a Class D felony, which is punishable by up to seven years in prison. In an indictment unsealed last Thursday, Jason E. Monet, 43, of Stamford, Conn., was also charged with two other felonies, leaving the scene of an accident in which a serious injury occurred and vehicular assault. The driver of the motorcycle, Sidney R. Hughes, 38, of Montauk, suffered multiple fractures, including a severely compounded thighbone, and continues to have trouble standing. He has had several surgeries and has three more scheduled in the coming weeks. According to Mr. Hughes, he lost about 50 percent of his blood in the accident, and a piece of the BMW had to be surgically removed from his body. Mr. Monet will be arraigned on the felony charges in Central Islip next Thursday, in the courtroom of Acting Supreme Court Justice Fernando Camacho, who is expected to reset bail. Mr. Monet has been free after posting $1,000 bail the morning after his arrest. Barry S. Jacobson, Mr. Monet’s attorney, said Monday that he was happy the case had been moved from East Hampton, despite the new felony charges. In Mr. Monet’s previous court appearances, in East Hampton, as many as 20 members of the Enders East Motorcycle Club were in the courtroom. “They have been very respectful,” Mr. Jacobson said of the bikers, who wore the colors of their various clubs, but, he said their presence “would make it difficult to select an impartial jury.” According to the accident report, Mr. Monet was driving west on Napeague at about 10 p.m. on June 21 when he made a left turn across the highway into the Ocean Vista Resort, where he and a friend, Kadria Idris Sadik-Kahn, were guests. The report states that he admitted not having seen Mr. Hughes on his 2004 Yamaha motorcycle, which was headed east. The cycle and front grille of the BMW collided, and Mr. Hughes was thrown about 100 feet, landing by a second gravel driveway at the resort. The impact is reported to have caused serious damage to Mr. Monet’s car, and he is alleged to have continued to drive into the resort parking lot, leaving a trail of parts and fluids leaking from the engine. On Saturday, Mr. Hughes, speaking on the phone from his home in the Hither Hills area of Montauk, described his grand jury appearance. On Sept. 8, he said, he was asked to come to the Suffolk district attorney’s office “to talk.” He arrived at the Cromarty Criminal Courts Building in Riverside on Sept. 9, and was ushered before the grand jury. He said he answered questions from an assistant district attorney mostly about the aftermath of the accident, the injuries he suffered, and what he has gone through medically since. Three of the police officers who were on the scene that night also testified, Mr. Hughes said. He had been told by officers that he was coherent when police found him covered in a blanket provided by a resort guest. Although he has no memory of what was happening at the time, he said he had been told that the situation was chaotic and that Mr. Monet was nowhere to be seen. “I don’t wish the guy harm,” Mr. Hughes said of Mr. Monet. “It was a very bad mistake. I’m sure he thought he killed me.” According to the police, Mr. Monet told them he had had a beer that night. He took a roadside breath test, which read .19 of 1 percent, well over twice the legal limit, although such tests are not admissible in court, and Mr. Monet subsequently refused to take the Intoxilyzer 9000 breath test at police headquarters, which would have been admissible. Mr. Jacobson, whose office is in Queens, was critical of the East Hampton Town Police Department’s handling of the accident, saying it should have been considered a major crime scene. “I don’t believe there was an accident reconstruction done. There was no attempt to secure the scene,” he said. He anticipates a prolonged period of investigation and discovery and has hired a private detective of his own. East Hampton Town Police Capt. Chris Anderson had previously defended the work done that night, saying that any indictment would be the result of the police work. Moving the case from East Hampton to the courthouse at 400 Carleton Avenue in Central Islip presents a challenge for the members of the Enders East Motorcycle Club, who want to continue to have a presence in court. Justin Portell, a member of the club, said Saturday that the journey to Central Islip to show support for their friend was going to be difficult, especially if, as expected, the process drags on. However, Jim Barr, president of American Bikers for Awareness, Training, and Education, an advocacy group, who attended the earlier hearings in East Hampton, said, “We will have a presence there. I am very happy the district attorney has put the time and effort into this case.”