Casper, 63, was a member of the San Francisco Civil Service Commission, a prominent Bay Area Republican and longtime community leader.He was also a partner at the San Francisco law firm of Jacobs, Spotswood & Casper LLP. He died after being struck at about 7 p.m. Sunday by a vehicle described by witnesses as a white pickup.“It’s a terrible loss, it’s a loss not only for the commission but for the community and the state,” Dennis Normandy, president of the Civil Service Commission, said Monday morning after learning of Casper’s death.CHP officials said the driver of the white, Ford pickup didn’t stop after hitting Casper, who went for an evening run while spending the weekend near the Russian River with friends.CHP investigators are focused on a truck captured on video from a security camera in front of Korbel Champagne Cellars. The pickup was heading eastbound past Korbel on River Road moments before the collision.Investigators released an image from the video of the vehicle, which matches descriptions of the one involved in the hit-and-run. The pickup appears to be a white, four-door Ford F-150 with a short bed and perhaps with gold trim, CHP Sgt Robert Mota said.“We’d certainly like to track it down and talk to the person,” Mota said. “If anybody knows of anybody with that type of vehicle who was out there and was headed eastbound in the early evening, we would like to know about it.”Casper was staying with friends Gene and Linda Payne at Summerhome Park, a recreational resort community located on a quiet bend of the Russian River, just northwest of Forestville.There was no answer at the Paynes’ home and a dark green, late-model Jaguar that a neighbor described as Casper’s was still parked in front of the residence where he was staying.News of his death spread quickly at the resort. One neighbor, who lived next to the family that Casper was visiting, said the San Francisco attorney spent many weekends at the Summerhome Park resort.Several residents said they could hear the emergency sirens on the other side of the river Sunday evening.CHP officials said the truck that struck Casper would probably have fresh damage to one side and officers Monday were getting the information out to local residents to see if someone can identify the truck and driver, said Evans.In San Francisco Monday Mayor Edwin Lee ordered flags at City Hall to be flown half-staff in Casper’s honor until sunset Tuesday.“Don was the expert on the rules governing employment in the City & County of San Francisco and knew it better than anyone else,” Lee said in a statement. “He has arbitrated labor disputes and established wages, work rules, and benefits for our City employees. His contributions to our city are immeasurable.”A fourth-generation San Franciscan who lived in the city’s North Beach neighborhood, Casper had a long history of community involvement.He had strong roots in the local Italian-American community and had served as chairman of the board of Columbus Day Celebration since 1994.Casper was president of the St. Thomas More Society of San Francisco, an association of Catholic lawyers and jurists, in 1986 and has been a member of the Legal Affairs Advisory committee for the Roman Catholic Archdiocese.From January 1997 to June 2002, Casper was chairman of the San Francisco Republican County Central Committee. He also served on the California Republican State Central Committee.He was first appointed to fill a vacancy on the Republican committee in 1991 but was later returned by voters until 2000.That same year, then-Mayor Willie Brown appointed Casper to the Civil Service Commission, where he was vice president.Casper was an avid long-distance runner who had completed nine marathons.He was running along a stretch of the western thoroughfare across from Odd Fellows Park. This part of River Road has a five-foot shoulder on each side, with a steep hill extending from the roadway on the north side. The south side is bordered by a seven-foot embankment.The CHP asked anyone with information about the accident to contact Detective Mike Phennicie or Sgt. Robert Mota at 707-588-1400 or, after hours, CHP dispatch at 707-551-4200.News Researcher Janet Balicki, Staff Writers Randi Rossmann and Sam Scott contributed to this report.