Family and friends of San Francisco civil servant Donald Casper want the hit-and-run driver who killed him to come forward.
"Doing so will make things easier for you, our family and Donald's friends," said Bernadette Castagnola.
The 63-year-old Casper was struck and killed August 14 while jogging along River Road near Guerneville.
A security camera at a nearby winery captured an image of a 2004 to 2008 white Ford F-150 pickup with tan or gold trim that is believed to be the truck that hit Casper.
"There were some witnesses that were near the accident...and they described the vehicle to us," said Ofc. Mike Phennicie with the California HIghway Patrol.
Casper was the former chair of the San Francisco Republican Party and worked on the city's civil service commission for the past 11 years.
"I'm still very sad to this day about how such a kind and gentle man was taken away from us in a violent and senseless manner," said Mary Jung.
"Not only did the family lose a beloved family member, the city lost a great asset," said Morgan Gorono.
Casper's family is offering a reward of $12,500 for information leading to the whereabouts of the truck and the driver. Anyone with information is asked to call the California Highway Patrol at (800) TELL-CHP.