Road rage between two drivers traveling on Jefferson Avenue in Washington apparently led to the fatal shooting Thursday in the parking lot of a local grocery store.Brandon Daniel Thomas, 30, of 1513 Redfern Drive, Upper St. Clair, was taken into custody shortly after he allegedly shot 55-year-old Vaughn Simonelli twice in the chest in the lot at Shop 'n Save in Jefferson Court Plaza on Beau Street. Thomas, Washington police said, was one of several people who called 911 to report the shooting just before 4 p.m. “He was told to put down the gun and wait for police,” said city police Lt. Dan Stanek. Simonelli, of Henderson Avenue, Chartiers Township, was pronounced dead at the scene. Thomas was arraigned early Friday before District Judge Mark Wilson on a charge of homicide. Stanek said Simonelli was shot with a small-caliber handgun.Stanek said Friday calls started coming into the 911 center before the shooting of possible road rage on Jefferson between two drivers.“Thomas definitely got off Interstate 70 on Jefferson Avenue,” Stanek said. “We don’t know exactly where and what happened, but we believe it was between the 400 and 500 blocks.”Simonelli was driving an older, silver Pontiac Grand Prix, while Thomas was in a black 2006 GMC Hummer. Stanek said he does not know if the vehicles collided. Police obtained search warrants to go through each vehicle.Both vehicles ended up in the lot at Shop 'n Save, with Simonelli’s car behind Thomas’ vehicle. A witness told policethe shooter, later identified as Thomas, reached inside the Hummer and pulled out a handgun. He then reportedly shot Simonelli as the two men stood next to the vehicle.“It appears a verbal altercation turned deadly,” said Gene Vittone, Washington County district attorney.Whether Thomas acted in self-defense or if Castle Doctrine applies would be a decision to be raised by the defense, Vittone said.The district attorney praised the efforts of the city’s detective unit, including Stanek, Sgt. Chris Luppino and Detective Dan Rush.Police are still looking into why Thomas was in Washington. They also are looking into where Simonelli was going that afternoon. Thomas was taken to Washington Hospital to be checked after the shooting. Stanek said Thomas was examined as a precaution because he was quite upset. Stanek said it is not known if he was struck by Simonelli during the altercation.Stanek said police are interviewing new witnesses and again talked with the witnesses who came forward Thursday. They also want to talk with anyone who might have seen the road rage incident on Jefferson. Stanek said that likely occurred about 3:45 p.m.Police are checking surveillance cameras in the store lot. They also will be checking to see if any cameras captured the incident on Jefferson.Thomas is being held in the Washington County jail without bond. A preliminary hearing is tentatively set for Wednesday in Central Court.Anyone who might have seen any aspect of the confrontation between the two men, either on Jefferson or in the parking lot, is asked to call Stanek at 724-223-1386 or the detective unit at 724-223-4223, 724-223-4224 or 724-223-4225.